Yumemi Okazaki

Yumemi Okazaki is a college professor investigating the existence of magic with the goal of analyzing it and reporting her discoveries to the scientific community. When she arrives in Gensokyo aboard the Probability Space Hypervessel, the locals mistake her craft for ordinary ruins, an error that sets the events of Phantasmagoria of Dim.Dream into motion.

Yumemi Okazaki
RegularAlt Costume “ That's right; I've finally found the beautiful power called 'magic' in this world. I won't settle for just observations anymore. I'm going to take you back as a test specimen, study that power, and then make it mine!! „ ~ Yumemi Okazaki
Origin
Origin	Touhou Yumejikuu (Dream Spacetime) ~ The Phantasmagoria of Dim.Dream
Creator	ZUN
First Appearance	Phantasmagoria of Dim.Dream
Voiced by	N/A
Characteristics
Species	Human
Gender	Female
Pronouns	She/Her
Sexuality	Unknown
Age	18
Birthday	Unknown
Height	Unknown
Weight	Unknown
Ethnicity	Likely Japanese
Status	Alive
Alignment	Chaotic Neutral
Archetype	Genius
Occupation	Comparative Physics Professor
Time Period	Futuristic
Language	Japanese
Combat Style	Scientific Magic
Homeworld	Different Probability World
Relationships
Affiliations	Chiyuri Kitashirakawa, Gensokyo Chiyuri Kitashirakawa, Alternate Yumemi Okazaki, Reimu Hakurei, Marisa Kirisame, Ellen, Kotohime, Kana Anaberal, Rikako Asakura
Enemies	Reimu Hakurei (Formerly), Mima (Formerly), Marisa Kirisame (Formerly), Ellen (Formerly), Kotohime (Formerly), Kana Anaberal (Formerly), Rikako Asakura (Formerly)

Background

This dropdown contains the synopsis of Yumemi Okazaki’s story. Read at your own risk as you may be spoiled otherwise!

Phantasmagoria of Dim.Dream English TranslationJapanese “ Touhou Yumejikuu Backstory Deep in the mountains in a country in the East, the Hakurei Shrine was mostly peaceful. The shrine maiden of the Hakurei Shrine, Reimu, was always getting wrapped up in strange circumstances (though it should be noted she was a bit strange herself), so her free time was when things were peaceful. Reimu: "Ah, what am I going to do with all this time on my hands. I wonder when something exciting is going to happen." When the protagonist is idle, something is required to happen. Reimu thought she'd get out of the shrine for a while instead of sweeping the garden, and so stumbled upon some ruins. Reimu: "Wait, what are these ruins doing next to the shrine. They weren't there yesterday!!" (something happens!) Mima: "Oh, Reimu. So you came, too." Reimu: "Great, it's Mima. Hmm, actually, it looks like there's a lot of people here ... " Reimu: "What is it with this ruins, anyway?" ... Mima: "It's said that something is asleep deep in these ruins that will grant happiness to whoever comes to visit it." Reimu: "Whatever, that sounds like something someone would say to get people to join a cult. Besides, none of this was even here yesterday. So what's up with that so-called prophesy?" Mima took out a folded piece of paper from her pocket. Reimu took it and unfolded it. This was written on the paper: The ancient ruins: "Fantasy Ruins" Grand opening, 10am today 　　　　　　　　　　　　　　　　　　　　　　　・・・・ To you who visit the ruins, we present something to make you happy. Our sincere thanks to everyone who stops by. Reimu: "Hm!" Reimu: "What's with these pamphlets? (How is this some sort of ancient prophecy?) How can ruins have a grand opening? And none of this was here yesterday! How can you all be taken in by something that's so obviously suspicious!?" Marisa: "Hm, so Reimu's not interested. That must mean..." Reimu: "...Who said I'm not interested?" Reimu: "Er, actually, I'm pretty busy (not), but having ruins suddenly pop up here is a pain to deal with. I have my complaints, you know." Mima: "Isn't it almost time for the grand opening? I don't see an entrance anywhere. I guess we'll have to wait for now." Reimu: (Man, when did this... well, I guess this is pretty normal around here... huh?) Reimu: " ... it looks like there's a notice posted over here." Marisa: "Wow, really? Hey, what's it say?" Inside the Fantasy Ruins Capacity: 1 person The capacity must be strictly observed. If the capacity is exceeded, then we can no longer guarantee the existence of these ruins in this dimension Reimu: " ........ ?" Mima: " ... so, that means ... " Marisa: "fufufu ... " All together: "The battle is on!!!" „ ~ Phantasmagoria of Dim.Dream Prologue English Translation “ 東方夢時空バックストーリー ここはとある東の国の山の中、博麗神社はおおよそ平穏だった。 博麗神社の巫女、靈夢は、実は変なこと巻き込まれ体質だった（本人もちょっと変）ので、変なことが起こらないと暇でしょうがないのである。 靈夢「あ～ぁ、ひまでしょうがないわ、なんかどひゃー　っていうようなことおこんないかしら。」 主人公が暇なときに、なにも起こらないはずがない。 庭を掃除しようと神社から出てみると、靈夢は遺跡を発見したのだった。 靈夢「なんで、神社の隣に遺跡があるのよ。昨日まで無かったのに！！（どひゃー）」 靈夢「げげ、魅魔。それに、よくみるといろんな人がいる～」 靈夢「一体なんなの、この遺跡は～」 ・・・・ 魅魔「古くからの言い伝えによると、この遺跡には来た者をしあわせにする何かが、眠ってるみたいよ。」 靈夢「なによ、その怪しげな宗教の勧誘みたいな言い伝えは。それに昨日までこんなもん無かったわよ。なのになんなのよ～、その言い伝えってのは～。」 ポケットから折りたたまれた紙を取り出す魅魔。靈夢がその紙を広げてみる。その紙にはこうかかれていた。 いにしえの遺跡、‘夢幻遺跡’ 本日１０時　開店 .... この遺跡に訪れた方には、あなたをしあわせにする何かを プレゼントします。皆さんのご来店を心よりお待ちしております。 靈夢「どてっ☆」 靈夢「なによ～、このチラシは～（どこが古くからの言い伝えよ～）。遺跡が開店～？　しかも、昨日まで何も無かったのに～。　あんたたちは、こんないかがわしいチラシに騙されて、のこのことやってきたの～！」 魔理沙「なるほど、靈夢には、興味が無いのね。ってことは・・・」 靈夢「・・・だれが、興味が無いなんていったのよ。」 靈夢「私はいそがしいんだけど（嘘）、こんな所に遺跡ができちゃったら迷惑だわ。ちょっと文句を言ってくる。」 魅魔「まだ、開店してないわ。それに、入り口が見当たらないの。とりあえず待ちね。」 靈夢（やれやれ、何でこんなものが、ま、いつものことだけどね・・・ん？） 靈夢「こんなところに、立て札があるわ。」 魔理沙「えっ、ほんと？　なになに・・・」 夢幻遺跡内　定員　１名まで それ以上は、認められません 規定人数以上、入場された場合 この時空での遺跡の存在は保証 出来ません 靈夢「・・・・・・？」 魅魔「って、いうことはー」 魔理沙「ふっふっふっ」 一同「　　勝負よ！！！」 „ ~ Phantasmagoria of Dim.Dream Prologue Japanese In Phantasmagoria of Dim.Dream, Yumemi serves as the final opponent faced by the player. Due to Chiyuri spreading false information, Yumemi offers to grant the player a wish if they win, both out of confidence in her own abilities and as an apology for her assistant’s conduct. After her defeat, she nearly attempts to use a bomb capable of destroying the world, but Chiyuri intervenes and stops her. Yumemi then honors her promise and fulfills the player’s wish. In Yumemi’s own scenario, after defeating all other challengers, she returns to the Probability Space Hypervessel, where she is almost attacked by Chiyuri. After scolding her, they are confronted by a third individual: a clone of Yumemi created by Chiyuri while tampering with the ship’s systems. Yumemi reprimands Chiyuri once more before battling her clone and ultimately emerging victorious. Following the conclusion of Phantasmagoria of Dim.Dream, Yumemi is expelled from the university where she worked for proposing the existence of magic as a legitimate theory. Afterwards, she and Chiyuri return to Gensokyo, with it being implied that they remain there. It's shown in every ending that's not the Chiyuri one that when they return to Gensokyo that they meet with Reimu, implying Reimu's route was the canon one.

Name Meaning

Yumemi Okazaki (岡崎 夢美) is her full name. Her name contains similarity to names used by several characters in other Japanese works released prior to Phantasmagoria of Dim.Dream. These include Yumimi Yoshizawa from Yumimi Mix, Sayori Okajima from Sayori na Parallel, and Marian Ezaki from Apple Paradise.

Her family name, Okazaki, is also similar to the surname of Japanese biologist Reiji Okazaki, as well as the Okazaki fragments associated with DNA replication.

Appearance

General Description: Yumemi Okazaki is a young woman with a composed and academic appearance, presenting herself in a formal outfit that blends scholarly and ceremonial elements. Her overall design emphasizes neatness and symmetry, with a consistent use of layered clothing and coordinated colors across her appearances.

Facial Features: Yumemi has sharp red eyes and long dark red hair that is kept tidy and falls smoothly behind her shoulders. Her facial features are narrow and refined, giving her a serious and focused expression. In her alternate color variation, her hair is blond and her eye color changes to yellow, while her facial structure and expression remain otherwise unchanged.

Clothing/Outfit: Yumemi’s standard outfit consists of a white shirt worn beneath a dark red vest, fastened at the collar with a bright red bow tie. Over this, she wears a long dark red cape that drapes over her shoulders, paired with matching cloth shoulder coverings that rest along her upper arms. Her skirt follows the same dark red color scheme, completing a uniform and orderly appearance.

In her alternate outfit, the overall design remains the same, but the color palette changes significantly. Her vest, skirt, cape, and shoulder cloths are black with purple trim along the edges. The interior lining of her cape is red, creating contrast with the darker exterior. Her bow tie remains red under normal circumstances.

Special Features: Yumemi’s bow tie exhibits a brief visual change during certain special actions, shifting from red to purple while she is performing an attack. This change is temporary and does not affect her standard appearance outside of these moments.

Alternate Forms/Outfits: Yumemi has a color-variant outfit that alters her hair color, eye color, and clothing palette while preserving the same overall design and structure. Aside from these color changes and the temporary bow tie variation during special actions, her appearance remains consistent.

Personality

• Intellectually Driven and Analytical: Yumemi approaches the world through a strict scientific lens, shaped by her role as a comparative physics professor. She is deeply committed to theoretical understanding, particularly the idea of a unified framework that explains all known forces, and she treats unresolved phenomena as problems to be examined rather than mysteries to be accepted, which is the basis behind her writing her Unified Theory of Magic.

• Skeptical yet Curious: Despite originating from a world where all physical forces are fully proven, Yumemi fully believes an unknown force exists outside the Grand Unified Theory. Her interest in “magic” stems not from belief or faith, but from scientific curiosity and a desire to challenge what she sees as incomplete knowledge. She is proven right by entering the world of Gensokyo.

• Proud and Sensitive to Criticism: Yumemi takes her academic credibility seriously and reacts strongly to ridicule or dismissal from the scholarly community. Being mocked for her ideas has her vow revenge against the scientific community.

• Short-Tempered: While generally composed, Yumemi becomes visibly irritable when her work, equipment, or authority is interfered with. She is constantly punching Chiyuri whenever seh does something wrong or makes a mistake.

• Pragmatic and Decisive: When confronted with serious complications (such as the existence of another version of herself) Yumemi focuses on resolving the issue quickly to avoid being a criminal. She is willing to consider extreme solutions such as killing her alternate self to avoid trouble.

Goals

• Prove her Unified Theory of Magic in her world (Failed).

Relationships

Close Relationship

Chiyuri Kitashirakawa

Chiyuri is Yumemi’s assistant, entrusted with various tasks to support Yumemi’s research and data collection. Their relationship is informal and frank, with both being blunt about their opinion on the other, normally resulting in Yumemi hitting Chiyuri.

Minor Relationships

Ruukoto

Ruukoto is a maid robot created by Yumemi. She formerly served Yumemi but was later owned by Reimu Hakurei Phantasmagoria of Dim.Dream.

Mimi-chan

Mimi-chan is a weapon and creation of Yumemi's. She was later given to Marisa Kirisame in Marisa's route of Phantasmagoria of Dim.Dream. As a canon route is very hard to determine and it very likely being Reimu's route if any route is canon, it is unknown if Marisa has Mimi-chan in current time.

General Information

Name: Yumemi Okazaki

Nicknames: Master (By Chiyuri), Professor

Titles: Fantasy legend

Origin: Touhou Yumejikuu (Dream Spacetime) ~ The Phantasmagoria of Dim.Dream

Overall Series: Touhou Project

First Appearance: Phantasmagoria of Dim.Dream

Company: ZUN Soft

Creator: ZUN

Actor: N/A

Gender: Female

Sexuality: Unknown

Pronouns: She/Her

Handedness: Left-Handed (Official art has her aiming and shooting her attacks with her left-hand)

Age: 18

Birthday: Unknown

Time Period: Futuristic (Noted that the science from her world surpass the main one by 500 years, and she notes the science of the main world is much more primitive then hers. It's noted in their world that one graduates from college at 11 and leaves the graduate school at 13)

Timeline: Outside World (There are worlds called "Probability Worlds" by Yumemi, stating that those and parallel worlds are one and the same, Yumemi and Chiyuri come from a different probability world then the one of Gensokyo)

Homeworld: Outside World

Residence: Gensokyo (At the end of the game, she returns to Gensokyo to learn more about magic, being shown in Reimu's post-credits ending)

Story Role: Hidden Antagonist

Legacy: Global Legacy in her world (She's a well-known comparative physicist at a university, attempting to prove that her theory of magic exists)

Influence: Personal Influence

Language: Japanese (As she is able to speak with Reimu and co.)

Ethnicity: Likely Japanese (Her name is a common Japanese surname meaning "mountain")

Religion: N/A

Classification: Captain of the Ship

Species: Human

State of Being: Regular

Physiology: Humanoid Physiology

In-Universe Creator: Unknown

Occupation: Comparative Physics Professor

Combat Style: Scientific Magic

Affiliations: Chiyuri Kitashirakawa, Gensokyo Chiyuri Kitashirakawa, Alternate Yumemi Okazaki, Reimu Hakurei, Marisa Kirisame, Ellen, Kotohime, Kana Anaberal, Rikako Asakura

Enemies: Reimu Hakurei (Formerly), Mima (Formerly), Marisa Kirisame (Formerly), Ellen (Formerly), Kotohime (Formerly), Kana Anaberal (Formerly), Rikako Asakura (Formerly)

Height: Unknown

Weight: Unknown

Status: Alive (Noted by ZUN that characters from the PC-98 games have probably retired and are warmly watching over things from various places nowadays)

Alignment: Chaotic Neutral (Yumemi is willing to prove her theory of magic to the scientific world that she is willing to kidnap the magic users that she comes across to use as a test specimen, study the power and make it hers)

Threat Level: Street Threat

Potential

• Type(s) of Potential: Fixed Potential
• Level of Potential: Fixed
• Description: As Yumemi's attempts with magic are through purely artificial means, she is limited by her scientific magic.
• Limitations: Standard limitations.

Archetypal Tiering: Genius

Codex Statistics

Grade: A

Tier: 10-B, Far Higher with Scientific Magic. 5-B with Fourth-Dimensional Positron Bomb

Cardinality: Finite

Dimensionality: 3-D

Power Source: Scientific Magic (An imiation of the real thing, using positively charged protons and light waves)

Attack Potency: Average Human level, Far Higher with Scientific Magic (Her story mode showcases that, she can fight multiple magic users back to back with the use of scientific magic and potentially even defeat them, although canon routes showcases her scientific magic truly pales in comparison with the real thing. Noted to not make light of the power of her science as she could blow up the planet at any moment). Planet level (Buster) with Fourth-Dimensional Positron Bomb (Has a fourth-dimensional Positron Bomb capable of destroying the entire world, though she notes she has no intentions of actually using it)

Durability: Average Human level

Striking Strength: Average Human Class

Lifting Strength: Average Human Class. Class Z with Preparation (Created a device to stop the moon in place so that Mima could always be empowered by it, calculating this in seconds)

Travel Speed: Average Human Speed on foot, Superhuman flight speed (Can keep up with other characters flight speeds, where they can reach across long distances due to being able to fly)

Attack Speed: Superhuman

Reaction Speed: Superhuman

Stamina: Superhuman (Her story mode showcases that, she can fight multiple opponents back to back without showing any signs of tiring at all)

Range: Standard Melee. At least Tens of Meters with Curtain Fire (Can send out dozens of energy projectiles along with multiple crescent shaped moons directly that travel these distances while the opponent is flying). Planetary with Fourth-Dimensional Positron Bomb (Has a fourth-dimensional Positron Bomb capable of destroying the entire world, though she notes she has no intentions of actually using it) & Preparation (Created a device to stop the moon in place so that Mima could always be empowered by it, calculating this in seconds)

Intelligence: At most Metagenius Intelligence (Yumemi teaches comparative physics at a university at the age of 18. The average person in Chiyuri and Yumemi's world graduates from college at 11 and leaves graduate school at 13, vastly outperforming the real worlds ages. Yumemi is the captain of the Probabiliy Space Hypervessel, a ship she built to access different probability worlds, parallel worlds that are one and the same. Used her scientific magic as an imiation of real magic, which she uses positively charged protons and light waves in order to imitate it. Created a device to stop the moon in place so that Mima could always be empowered by it, calculating this in seconds)

Knowledge: At least Master level

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Powers and Techniques

Innate AbilitiesWith Equipment

• Superhuman Physical Characteristics
  • Superhuman Speed
  • Superhuman Reaction
• Genius Intelligence
• Human Achievements (Yumemi teaches comparative physics at a university at the age of 18)
• Vehicular Usage
  • Air Vehicles: Yumemi is the captain of the Probabiliy Space Hypervessel, a ship that doesn't float along the water, or glide through the clouds, or drift through space, but instead is a probability space hypervessel, used to travel to alternate worlds and time periods.
• Preparation (Created a device to stop the moon in place so that Mima could always be empowered by it, calculating this in seconds)
• Sheer Will (When asked how do the characters have multiple "lives" in the game, ZUN notes that it's guts, so if they earn more points, it's them having more guts to continue fighting, while this may have initially been merely a joke, ZUN has elaborated that canonically, anytime Reimu and the gang are defeated, they challenge again however many times they want, but on the youkai side, they do not challenge again after being defeated and are not attached to the results of winning or losing)
  • Second Wind
• Breaking the Fourth Wall (Noted how for the sake of accuracy, if she lost to her other Yumemi self, the exact same thing would've happened where the weakened one's energy would return to the other, before quietly saying to herself this is wrong, she would've just game overed. Touhou characters constantly acknowledge being a stage boss. It's likely her apologizing to any players that may be aliens or maggots)
• Flight (Yumemi is capable of flying off the ground and moving around to shoot out energy projectiles)
• Cartoon Physics (Gensokyo is a world that lacks and defies common sense, where characters can explode, this is even acknowledged with ZUN roleplaying as the characters in-universe that they explode upon defeat. Despite this they will still come back, even human characters that do not have regeneration)
• Non-Standard Interaction
  • Metaphysical Interaction: She is capable of harming Youkai like Mima with her attacks, where Youkai's bodies in truth are just their souls.
• Non-Standard Damage (She is capable of harming Youkai like Mima with her attacks, where it's noted that one cannot defeat spirits or devilish powers without a weapon with an unnatural amount of spiritual power such as the Yin-Yang Orb)
• Non-Standard Defenses (She is capable of takings hits from Youkai, like Mima where a youkai's attacks damage one to a scale where they cannot recover from natural means)
• Observation
  • Unconscious Manifestation: Gods and buddhas are no more than youkai, yet youkai are hated while gods are worshipped, all being due to humanity deciding it should be that way. The form Nue takes has changed due to the various ways people have observed her. Humans created reasoning in order to explain all natural phenomena, thus every phenomena that could be observed therefore belongs to the human race, due to this, humans come to believe all but one, or perhaps even all forms of reasoning were false, spawnning youkai who were born from the natural phenomena and thoughts people have about them.
  • Truth Manipulation & Information Manipulation (Truth is built upon information just like a tower is built upon sand, most of the truths that are known are built upon information, thus truth is easily changed by informationa nd there's no such thing as information that concepts only but the truth as truth itself is the ultimate illusion, one that does not exist in Gensokyo)
• Curtain Fire
  • As a Boss
    • Multi-Directional & Rapid Fire: Can send out dozens of energy projectiles along with multiple crescent shaped moons directly at the opponent to overwhelm them.
• Nullification & Erasure
  • Projectile Nullification & Physical Erasure: Yumemi can fire out attacks that fully erase bullets being shot towards her.
• Charged Attack (With the Gauge Attack System, when the Spell Gauge is held down, Yumemi can charge the gauge to the maximum amount, when released, the attack is in accordance to the amount of the gauge that's charged)
  • Explosion Manipulation (Her charged attack shoots a small energy projectile that explodes upon contact)
• Matter Manipulation & Light Manipulation (Yumemi uses scientific magic as an imiation of real magic, which she uses positively charged protons and light waves in order to imitate it)
• Fire Manipulation (Yumemi can send out fireball attacks from blue fireballs or normal ones while red ones have been sent back at least once when she gets a bigger combo or has erased a lot of bullets)
• Information Manipulation (Human's life information is the ultimate impurity, being apart of Earthly information, which is the information of all living things. The reason why this is never shown is that the Asama Joue Moutain is a shrine that neutralizes human impurities, where if the human information cannot be processed it will throw the Lunar Capital into disarray)
• Link Manipulation (Strong Emotions can be contained in objects that can connect between the main world and the netherworld)
• Spirit Manipulation (The bombs used are referred to as spiritual attacks, being directly called spiritual attacks)
  • Explosion Manipulation (When bomb users are cornered from attacks they cannot repel with regular attacks they can release a massive spirit explosive that destroys all objects on screen, along with killing all enemies on screen)
  • Magnetism Manipulation (When using a bomb, all items on screen will be attracted towards the user)
  • Perception Manipulation (When using a bomb the screen flashes white and an image of Yumemi can be seen)
    • Astral Projection (Can send an astral image of herself to attack the opponent on the other screen while on her screen)
      • Afterimage Creation (The astral image can move so fast it makes afterimages)
  • Logic Manipulation (The Great Hakurei Barrier is a boundary of common sense, which things with high spiritual power in the cause to waver)
  • Nullification & Erasure
    • Projectile Nullification & Physical Erasure: Bomb users can use a bomb to nullify & erase all projectiles on screen. This makes the enemy incapable of shooting out any further projectiles until the bomb's duration is done.
  • Invulnerability
    • Physical & Metaphysical: When a character uses a bomb, they are temporarily invincible to all attacks and is allowed to attack freely herself.

• Resistance to
  • Purification (Eirin noted that only humans could solve the incident with Junko as youkai being completely impure could not eevn see her, with it being noted that non-humans cannot get close to her, where Junko's powers of purification allows her to kill one unconditionally, removing all impurities from them, with impurity being the concept of life and death where to lose one's impurity is to lose both life and death, it was also shown a metallic spider's march of purification caused all the trees withering before one's eyes and not one blade of grass was left in the spider's tracks)
    • Conceptual Manipulation

• Cloning (Has machines that can make a clone of herself)
• Dimension Manipulation & Explosion Manipulation (Has a fourth-dimensional Positron Bomb capable of destroying the entire world, though she notes she has no intentions of actually using it)

For Unique Equipment:

With Probability Space Hypervessel

• Probability Manipulation, Dimensional Travel & Time Travel (There are worlds called "Probability Worlds" by Yumemi, stating that those and parallel worlds are one and the same, with the Probability Space Hypervessel being able to access different probability worlds)
  • Extrasensory Perception & Radar Sensing (Yumemi uses the device to search for power that lies outside the Grand Unified Theory)

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Equipment

Probability Space Hypervessel

The inside of the Probability Space Hyperverssel

• Description: The Probability Space Hypervessel is a colossal trans-dimensional craft commanded by the scientist Yumemi Okazaki. It was used to voyage from the Outside World to the hidden land of Gensokyo with the sole purpose of obtaining scientific proof of magic's existence. Its advanced technology is so far beyond local understanding that it was initially mistaken for mundane ancient ruins.
• Appearance: Its exterior can project camouflage fields to mimic local rock and foliage, contributing to its "ruins" disguise. The inside of it seems to be large enough to hold a moon in the background, along with what seems to be a space-like backdrop when fighting against Chyuri and Yumemi.
• Usage: The vessel's primary function is to navigate and transit through "probability space," a theoretical dimension allowing travel between mutually exclusive realities and timelines—such as from the secular Outside World to the magical realm of Gensokyo. During the *Phantasmagoria of Dim.Dream* incident, its interior was used as a tournament arena, where Yumemi and crewmate Chiyuri Kitashirakawa tested Gensokyo's inhabitants to collect data on magical energy.
• Function: The Hypervessel operates on principles that manipulate probability fields and localized spacetime. This allows it to bypass conventional physical barriers and the Great Hakurei Barrier. It is equipped with advanced sensors for detecting anomalous energy signatures (i.e., magic), defensive shields, and internal environmental systems that can reconfigure spaces for combat or study. It is also implied to possess significant firepower.
• Notable Traits: The vessel is also capable of temporal travel, placing Yumemi and Chiyuri as visitors from the future. This is supported by Rikako Asakura's analysis that its technology is centuries ahead of even Gensokyo's isolated development, and Chiyuri's title as "Resident of Fantasy That Runs Through Time." The ship serves as their mobile laboratory and home.

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Fourth Dimensional Positron Bomb

• Description: A bomb made by Yumemi, likely for cases where the enemy is too powerful as a last resort, though she notes she was merely joking when threatening to use it against any of the playable characters that defeated her.
• Appearance: It is never directly seen, only mentioned.
• Usage: Yumemi describes it as a bomb capable of destroying the entire world.
• Function: As it is noted to be fourth-dimensional positron bomb, it likely uses positrons from the fourth dimension in order to fuel it to have such power such as destroying the entire world.

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Ruukoto

• Description: A nuclear-powered robot maid given to Reimu Hakurei as her granted wish at the end of Phantasmagoria of Dim.Dream. Originally created to serve Yumemi Okazaki, Ruukoto was transferred to Reimu to help with daily shrine cleaning duties.

• Appearance: Ruukoto has light green hair and wears a light-blue and white maid uniform. Her outfit includes a red bow, and a yellow radiation warning symbol is displayed on her back, indicating her nuclear power source.

• Usage: Intended to assist with maintenance and cleaning of the Hakurei Shrine. Despite being assigned domestic responsibilities, she is not particularly efficient at performing household tasks, often requiring Reimu to do the work herself.

• Function: Serves as a robotic maid and helper unit, designed to follow commands and carry out basic chores around the shrine. Her role is primarily supportive rather than combat-oriented.

• Notable Traits: Nuclear-powered construction and status as a robot maid set her apart from typical shrine helpers. She is a parody of other android maids, and her poor cleaning ability contrasts with her intended purpose. It is unclear whether Reimu still keeps Ruukoto due to her origin in the PC-98 era.

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Mimi-chan (ミミちゃん)

• Description: Mimi-chan is a sentient female intercontinental ballistic missile (ICBM), originally the property of the scientist Yumemi Okazaki. She appears exclusively in Marisa Kirisame's good ending in Phantasmagoria of Dim.Dream, gifted as a "weapon from the outside world." She is a unique case in the Touhou Project as a sapient, non-humanoid artifact of futuristic technology.
• Appearance: Mimi-chan is a large, primarily white missile with standard aerodynamic fins. Her most distinctive feature is the simple, cartoonish face painted on her nosecone: two large, circular black eyes, a single-line red mouth, and a red tip serving as her nose. This cheerful design is a direct reference to the identically named and designed missile from the 1986 manga Don't Leave Me Alone, Daisy.
• Usage: Her intended function as a weapon of mass destruction is unclear in practice within Gensokyo. Marisa, having no knowledge of advanced ballistic weaponry, opted to use Mimi-chan as a makeshift flying vehicle, literally riding atop the missile. This demonstrates that Mimi-chan retains her primary propulsion systems and is capable of controlled, piloted flight, albeit in an unconventional manner.
• Function: As a sentient ICBM, Mimi-chan presumably possesses an advanced guidance system, powerful rocket engines, and a thermonuclear warhead, though the latter's status is unknown. Her sentience implies a complex onboard computer or an infused spirit, allowing for autonomous operation and interaction.

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Notable Techniques

Note: The attacks listed here are charge attack and bombs from the game, with only their name listed, this is far before "spell cards" existed, thus there is not much info on their attacks.

Spell Card Charge

夢幻爆弾
Dream Bomb

Owner

Yumemi Okazaki
—

Comment

威力高

Translation

Spell Card Charge Max

スピードアップ ＋ ショット強化
Speed Up + Stronger Shot

Owner

Yumemi Okazaki
—

Comment

Translation

Spell Card EX

苺クロス
Strawberry Cross

Owner

Yumemi Okazaki
—

Comment

最強の十字架

Translation

Spell Card Lv2

全方向弾×６
(Omnidirectional Bullets × 6)

Owner

Yumemi Okazaki
—

Comment

見切るしか。

Translation

Spell Card Lv3

全方向弾×６
(Omnidirectional Bullets × 6)

Owner

Yumemi Okazaki
—

Comment

見切るしか。

Translation

Spell Card Boss

夢幻伝説
Fantasy Legend

Owner

Yumemi Okazaki
—

Comment

まさに最強クラス

Translation

Spell Card Bomb

科学の魔法陣
Magical Position of Science

Owner

Yumemi Okazaki
—

Comment

ボムの性能は全員いっしょ

Translation

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Other

Standard Tactics: Yumemi utilizes her preparation and scientific magic in combat, shooting out dozens of projectiles against the opponent.

Weaknesses: Nothing notable.

Note

• Any translations from en.tohouwiki.net are considered fine to use as they all fall under Project Translations, a fan translation team that have translation guuidelines and rulesets, along with moderators that directly overlook and proofread English translations to check for machine translations.
• Yumemi's statements can be taken with credibility, not only do the science from her world surpass the main one by 500 years where she notes the science of the main world is much more primitive then hers, but her world has already fully proven the existence of Grand Unified Theory and Yumemi herself notes that her theory was proven right by seeing magic.
• Despite Gensou Narratograph being directly noted to be an "unofficial Touhou tabletop RPG", ZUN has directly participated in the RPG and noted the way Reimu acts during his session is how canon Reimu would act, thus character actions done by him and mechanics are fine to use.
• Even if characters have not showcased using a bomb, they should all be able to use bombs, as bombs are realistically just spiritual attacks and to even be able to fight the non-human entities, requires a weapon with an unnatural amount of spiritual power such as the Yin-Yang Orb, meaning everyone that is non-human or is fighting non-humans is using spiritual energy.

Explanations

Canoncity of Touhou Project

The Touhou Project franchise canoncity mainly falls under any media worked on by ZUN are official and canon to the overall lineup.

There are various aspects constantly debated about within the canon:

PC-98

Media like PC-98, has been noted by ZUN to be ignored as one can ignore derivative works. He has also said that anything prior to Embodiment of Scarlet Devil can for the most part be ignored and one can think of Embodiment of Scarlet Devil as the starting from a clean slate and starting a new series, he's also referred to Highly Responsive to Prayers as a study product. With this in mind, one would assume that PC-98 is thus non-canon to the Windows continuity of games.

However, ZUN has also directly stated PC-98 games are the same world as the Windows Games, stating that any contradictions that exist from PC-98 can be ignored from the retcon in Windows Era. While one argues ZUN noting the works are derivative works to be ignored and Embodiment of the Scarlet Devil should be seen as the starting point, these statements are moreso telling a fan to not worry about having to play PC-98 games or learn more about their stories.

It's also been noted in Embodiment of Scarlet Devil's おまけ.txt that the game chronologically is not too far from the previous title, which would be Mystic Square, the PC-98 title. ZUN has also directly brought back characters from PC-98 games, noting he wanted to bring back characters from before Embodiment of Scarlet Devil and notes any of the other older characters that don't appear have probably retired by now and are warmly watching over things from various places nowadays. When asked where Mima from PC-98 has gone, ZUN notes that he doesn't bring them back due to making things complicated and having potentially angry fans ask where she has been the entire time, he has also noted that there's not much use for characters like Genji as Reimu can fly now and also notes he is not dead. ZUN has also made mention to Genji probably living in the lake in the back of the shrine. In Touhou Sangetsusei ~ Strange and Bright Nature Deity, Reimu and Marisa were talking about glowing moss with Reimu saying it would be nice to transfer it to the pond in the back of the Hakurei Shrine and Marisa saying that she could make it grow there on the turtles' back, referencing Genji.

In Touhou 07 Perfect Cherry Blossom, when Alice meets Reimu, she tells her long time no see, noting that they've met before calling her "old friend". In Yuuka's mode in Touhou Project - Phantasmagoria of Flower View, Reimu directly references defeating Yuuka back in PC-98. If Yuuka defeats Marisa in the same game, she will note that Marisa has grown up quite a bit, when the last time she's seen her has been in PC-98.

Seeing as ZUN himself has directly said both PC-98 and Windows are in the same world and that characters directly acknowledged PC-98 events and reference characters from it, PC-98 is completely canon and any contradictions PC-98 have can be ignored.

Side Games Time Placements

Touhou 7.5 - Immaterial and Missing Power takes place between Perfect Cherry Blossom and Imperishable Night.

Multiple Playable Routes

In the series, there are multiple playable character routes, including some where the characters fight Reimu herself and defeat her, calling question into what route is canon. ZUN has elaborated that canonically, anytime Reimu and the gang are defeated, they challenge again however many times they want, but on the youkai side, they do not challenge again after being defeated and are not attached to the results of winning or losing.

In terms of how playable routes have went, some examples of canonically noted routes:

• In Reimu's profile on Perfect Memento in Strict Sense, it's noted that Reimu resolved the Scarlet Devil Mansion Incident alone.
• Reimu is also acknowledged to have resolved the Spring Snow Incident in Perfect Cherry Blossom, though it is not noted if she did this alone.
• Reimu claims she solved the Eternal Night incident, however if one asks her about the cause or the perpetrator, she'll only respond with ambiguous answers, it is also not noted if she did this alone.

With some of these examples, it is normally assumed that in some way Reimu has some part in resolving every incident and other routes are dubiously canon depending on what transpired.

Spell Card Rules

There are many cases of weaker humans beating stronger Yokai or vice versa within the Touhou series, this has been elaborated on in Reimu's profile on Perfect Memento in Strict Sense. Reimu introduced the spell card rules as the youkai had no way to defeat the Hakurei shrine maiden, making many youkai feel that their meaning to exist have dissapeared. The rules incoporate the following:

• Spell cards are techniques specially-named by the individual, and they must be declared upon use.
• The number of each party's spell cards must be determined in advance of a duel.
• The first party to have all of their spell cards beaten must admit defeat.
• The victor is entitled only to what was agreed upon before the duel. If they're not interested in what their opponent has to offer, they can refuse a duel.
• Winners should generally allow losers a rematch.
• Always prepare for the unexpected.

The original draft held these rules:

• Combatants will give names and meanings to the duel for the benefit of beauty.
• Combatants will declare the number of named duels before beginning.
• Combatants may not repeat attacks by relying on stamina.
• Combatants may not deliver attacks that do not have meaning. The meaning itself becomes the attack's power.
• In the case that a combatant loses a named duel, that combatant will admit defeat, even if he or she has strength remaining. No combatant may kill a human, even upon victory.
• Combatants will write the duel's name on paper in the format of a contract. By doing so, the above-mentioned rules become absolute. These papers will be called spell cards.

These rules allows for duels that feel almost like sport rather then a match, and have allowed for weaker fighters to challenge stronger ones, due to this though, it also has become possible for youkai to freely defeat Reimu without worrying about the consequences.

Due to them being written into cards and essentially affecting the ability and power of an attack, the spell cards are likely the thing binding attacks to specific properties.

Parallel Worlds

Parallel Worlds is a topic brought up at some points in the Touhou Project franchise, they are worlds called "Probability Worlds" by Yumemi, stating that those and parallel worlds are one and the same. This essentially means that parallel worlds in Touhou are based on the concept of probability. Yumemi and Chiyuri use a "Probability Space Hypervessel" in order to travel to alternate worlds and time periods, further showcasing that probabiliy serves an importance.

Magical vs. Physical Strength

There are multiple occasions of characters commenting on humans like Reimu being strong. Despite this Reimu showcases physical strength that isn't superhuman, such as the fact that she cannot cut a bamboo stick while Fujiwara direclty does in front of her.

This is due to the difference between magical and physical strength.

In works like Symposium of Post-mysticism, Yuugi Hoshiguma's profile has Suika directly state that Yuugi is weaker then her in magical powers, but stronger than her physically, lining a clear difference between magical and physical strength.

While one can be physically stronger then another, such as how Onis are physically the strongest, magic users are still able to keep up with them due to using a different form of attack.

An example can be found with Yuugi herself, when Reimu fights against her in Subterranean Animism, with her acknolwedging her strength, something Yuugi only does to those who are truly strong. This establishes even with spellcard rules, Yuugi considers Reimu a strong fighter. Reimu herself is very clearly not at an oni's physical strength, as she cannot do the things they can, however, her magical strength allows her to keep up with them.

To defend against magical based properties requires Non-Standard Defenses as it is acknowledged as not being something of standard physicality.

The Three Layers of Reality

In Chapter 27 of Curiosities of Lotus Asia, Reimu proceeds to explain how reality works to Rinnosuke and Marisa, where she explains in-depth the three layers of reality.

This conversation started from discussing the mechanism of fortune, where Rinnosuke attempted to posit that the future is predetermined and that Reimu's luck was her being able to calculate in an instant the predetermined future, however Reimu had a different explanation requiring her to lecture on the mechanisms of probability, in her explanation, the world is made up of three layers: the physical layer that moves in accuracy with the laws of physics, the second layer that moves with the spirit, and the third layer of memory which is the recollection of events that lies within all things. The memory layer rejects the loop of the physical and mental layers, the two layers the youkai conceive of the world which is why they believe history repeats itself and the future is predetermined. Since it's only possible to add to the memory layer, it's possible to completely recreate the past.

While the physical layer follows the laws of physics, the mental layer interprets the outcomes and the memory layer alters the probability, essentially creating the future, since it's impossible for memories to raech the same state as a point in the past, the future is not predetermined, thus when Reimu is able to predict how the dice will fall, she's not predicting the fall of the dice, the dice members the fact that she predicted how the dice would fall, thus due to this, Reimu entering the memory of the die-face greatly skews the results in Reimu's favor, where the results side with Reimu.

Thus the memory layer is essentially the most important layer that rejects the notion of loops from the previous two layers.

Trivia

• Yumemi Okazaki is pictured on the front cover of Phantasmagoria of Dim.Dream together with the entire cast of that game.

• Among PC-98 era characters, she is one of a select few to have a dedicated, full-sized portrait within the game. This artwork appears specifically when she activates her special attack.

• Yumemi is one of only two human characters to serve as a final boss in the series, the other being Sumireko Usami. Notably, Yumemi is the sole final boss who lacks any form of inherent supernatural power or magical ability.

• There is some argument that her home dimension might not be the "Outside World." that Sumireko Usami lives in. Her world is described as one where a grand unified theory of physics has been proven, and academic prodigies can complete graduate school by the age of thirteen.
  • However an argument against this is found in Magical Astronomy, set in the future of the Outside World. There, Maribel Hearn mentions that gravity has recently been unified with the other fundamental forces. As well with Gensokyo consistently being shown to be a non-linear area of time where people from any era can show up in, it is very much possible Yumemi is from the Outside World Sumireko comes from, just in the far future.

Gallery

• 

  Cover of Phantasmagoria of Dim.Dream, featuring Yumemi & others

Profiles

Touhou Project - Phantasmagoria of Dim.Dream

Profiles

★ Fantasy legend ... Okazaki Yumemi She teaches comparative physics at a university. She doesn't look like it, but she's already 18, which is quite young to be a professor. In Yumemi's world, all the forces such as gravity, electromagnetism, and atomic power have been resolved under a unified theory, which has been proven to explain all known forces in the world. Yumemi believes there may be a force that doesn't fit in this theory - "magic". However, when she announced her theory to the academic community, she became a laughing stock. Yumemi came to this world to get even with the academy, but...

★　夢幻伝説　　　　　　　・・・　岡崎　夢美 　　　　大学で比較物理学を教えている。これまた若く見えるが年は１８才、結構 　　　若くして教授をやっています。夢美達の世界では、重力、電磁気力、原子間力 　　　など、あらゆる力は統一できると証明され、それに当てはまらない力は無い、 　　　とされている。しかし、夢美は当てはまらない力、‘魔力’が存在すると考え 　　　学会に発表した、が、思いっきり笑われ、相手にされなかった。 　　　夢美は学会に復讐するために、この世界にやってきたのだが・・・

Touhou Project - Phantasmagoria of Dim.Dream

Misconceptions

Characters Have Flown Through Outerspace

One example of this is believed to be in Touhou 02's Stage 3 Scarlet Dream ~ Scarlet Dream where it displays stars and a space-like effect in the background, however this is actually the World of Fantasies, the world that lies between Makai and the human world, with Genji confirming this is definetely not outerspace as Reimu can breathe just fine there.

All Characters are Children

This is an argument that spawns from how small the characters look in different works, though this is moreso due to the "moe" artstyle Touhou tries to capture, in many of the manga characters look far older.

Majority of characters in the series are outright shown to drink alcohol on a daily basis, where one needs to be at least 20 years old under Japanese law to drink, where Japanese law requires no underaged characters to be shown drinking. This is even acknowledged in the series itself with a note saying alcohol is only for those over 20 years old. Thus if a character is ever seen drinking alcohol in the series, they are an adult.

The only direct non-adults in the series are Sumireko Usami, Chiyuri Kitashirakawa, and Hieda no Akyuu in her first appearance.

Youkai Control the world through both the mental and physical layer

This statement comes from a fan translation that says this in Curiosities of Lotus Asia.

While the statement seems clear cut, there is another translation used instead that makes more sense with the sentence.

It instead notes that most youkai concieve of the world through these two layers, which is why they believe the future is pre-determined and history repeats itself. This falls in line with the earlier disucssion of Rinnosuke claiming that he believes the future to be predetermined and Reimu needing to explain to him why that's not the case.

Song:

Strawberry Crisis!!

Battle Records

0 - 1 - 0

VictoriesLossesInconclusive

None.

• Reimu Hakurei - Fight
  • Conditions: None.
  • Location: Final Stage, Probability Space Hypervessel

None.

References

Expand here.