|“||The sunlight that rains down on the Earth is a nuclear furnace that will create new atoms. My ultimate nuclear fusion will burn up every body, heart, ghost, and fairy!||„|
|~ Utsuho Reiuji|
Utsuho "Okuu" Reiuji is a Yatagarasu (Hell Raven) from Touhou Project who can manipulate nuclear fusion, an ability that she got when Kanako Yasaka bestowed great power upon her to help with an industrial revolution project on the Youkai Mountain. Utsuho is one of Satori Komeiji's two pets, the other being her friend, Rin Kaenbyou, and lives with them and Satori's more powerful sister Koishi Komeiji in the Palace of the Earth Spirits located underground below Gensokyo. She also goes by the nickname of "Okuu" and her verbal tic is "Unyu". In her first appearance in Subterranean Animism, Utsuho wanted to use her new powers bestowed by Kanako to take over Gensokyo. This makes it worth noting that she was Touhou's first "true villain" in the fact that she had no other motive other than world domination, a common goal of villains in cartoons and kid's shows. She is also known for being an idiot, and doesn't seem to remember much.
Utsuho is a girl with long black/dark brown hair and red eyes. She wears a white short-sleeved shirt with a red eye with a cat-like iris on it as well as a green skirt and hair bow. She wears black socks with a large metal shoe worn on her right foot and a regular black shoe worn on her left one. She has large black wings and wears a white cape that hangs on her wings, and her cape has a spatial void on its inside. She also has a large arm cannon (referred to as a control rod) on her right arm, which she can use to blast out fire and solar rays.
- Satori Komeiji (Master)
- Rin Kaenbyou (Friend, Fellow Pet)
- Koishi Komeiji (Master's younger sister)
- Kanako Yasaka (Giver of Nuclear Powers)
- Suwako Moriya (Unknown)
Utsuho has the ability to control nuclear fusion. In battle, she uses this ability to create miniature stars and use them as projectiles ("miniature" compared to normal stars, but they are still some of the largest projectiles in the series). She can also use radiation as a weapon and shoot solar fire at opponents.
Her "control rod" can be used in a diversity of ways. She can use it as an energy blade by emitting a short-ranged burst of fire, as an energy cannon that fires gigantic solar beams (Giga Flare), or even smash the ground with it to create a wave of flaming geysers aimed at the opponent.
She can also envelop her body in flames and tackle her opponents, or overload her body with energy to create a giant explosion centered on her (Abyss Nova).
- A silhouette of Utsuho occupies the front of Subterranean Animism's jewel case.
- In ancient Chinese mythology, the three-legged crow is a mythical animal associated with the Sun, thought to be its guardian beast or, more often, the manifestation of the Sun's deity. This explains Utsuho's nuclear fusion power and association with heat.
- This myth of the three-legged crow and the fact that the crow tengu Aya Shameimaru calls her "hell crow" twice may be why people refer to her as a crow, even though she's a raven. (Actually, most Japanese don't distinguish raven from crow, except zoologists and curious people. The fact that both raven and crow are from the corvus genus doesn't help.)
- The red eye is proof that Utsuho obtained the power of fusion by absorbing the three-legged crow (Yatagarasu) because the three-legged crow's eyes are red, according to Chapter Three of Cage in Lunatic Runagate.
- Her "Third Leg" resembles an arm cannon. In Touhou Hisoutensoku, it is used as one.
- Utsuho appears to be the only final boss in a Windows game whose goal is explicitly conquering the world. A very common goal for villains in cartoons.
- Utsuho is also the only final boss in a Windows game who is a subordinate of an earlier boss (Satori).
- Utsuho's spell cards "Giga Flare" and "Mega Flare" share the name of the attacks used by the summon Bahamut of the Final Fantasy series.
- "Unyu?" (うにゅ?) has become her trademark sound, ever since she said it in the Extra Stage back story.
- Utsuho is the only final boss in a Windows game that gives the player a warning before the spellcard begins. "☢ CAUTION!! ☢" appears for a few moments with Klaxons blaring in the background.
- In Utsuho's Spell Cards, the background behind the trefoil is a photo of the Carina Nebula.
- Utsuho's spell card background also features a real-world picture of a cat on the trefoil. One reason ZUN might have included this in the background could be because of the wild cats that have colonized the abandoned city of Pripyat'. Pripyat' was the town created for the families of workers at Chernobyl, and after the catastrophe there the population was evacuated. Recent excursions back into the ghost town lead to the discovery of a small community of irradiated wild cats that live comfortably in the foundations of abandoned homes.
- Furthering the Chernobyl links, Utsuho could be a reference to the so-called Black Bird of Chernobyl not only because of her massive black wings, but also because the red eye in her chest, which was another trait of the Black Bird.
- And this "eye" in the center of her chest looks similar to one of J.R.R. Tolkien's creations, the Eye of Sauron.
- In Story of Eastern Wonderland's Stage 4, in the second part of the background, there was an orange-like shine that was shaped like the orb that Utsuho points to in her Subterranean Animism portrait.
- Two of her alternate palettes in Touhou Hisoutensoku resembles her master Satori and Satori's sister Koishi.
- Another palette resembles Kanako Yasaka.