|“||My five requests that so many humans in the past have failed to complete... How many of them can you fulfill?||„|
|~ Kaguya Houraisan, before the fight of Imperishable Night|
Kaguya Houraisan (蓬莱山 輝夜 Houraisan Kaguya) is a hero and one of the characters from the Touhou Project series who first appeared as the Final Boss of Imperishable Night.
She currently lives alone in the Bamboo Forest of Eientei with the exception of her friend Eirin Yagokoro and many rabbits.
Kaguya has dark brown eyes and very long black hair styled into a traditional princess cut. She wears dirty clothing including a pink shirt with long sleeves past her wrists, decorated with multiple white bows and a single violet bow, and a long, dark burgundy skirt decorated in yellow with bamboo and flower shapes. Her 5 Impossible Requests are seen floating around her, probably waiting for her order to engage in a Spell Card attack.
Kaguya is carefree and as of a result of spending her time alone in Eientei, lonely and bored, wishing to get visitors. When people come to meet her she is social and will tell them stories if given the chance. She is also arrogant, happily taunting Mokou, and confident, boldly attacking each of the characters during the events of Imperishable Night.
Kaguya was once a princess of the Lunarians, a race of people living on the Moon. She was exiled to Earth over a thousand years ago for the crime of using the forbidden Hourai Elixir to make herself immortal. Arriving on Earth one day, she was found by a bamboo cutter and dwelt among the humans she had once despised. Though the Lunarians looked upon humans with contempt, Kaguya came to love her new home. Tales of her unearthly beauty led men from all across the land to seek her hand in marriage, but none could successfully complete her trial of the Five Impossible Requests.
The first was to bring her the stone begging bowl of the Buddha from India. The second was to retrieve a jewelled branch from the island of Mount Hourai. The third was to seek the legendary robe of the fire-rat of China. The fourth was to retrieve a colored jewel from a dragon's neck. The final task was to find the legendary Cowry treasure of the swallows. However, unbeknownst to her suitors, she had already possessed these potent treasures.
After years of exile, powerful emissaries arrived from the Moon; Kaguya had been forgiven of her crime and it had been decided that she should return. Kaguya, however, had grown to love life on Earth and had no desire to return to the lunar capital permanently. Enlisting the help of her friend Eirin Yagokoro, Kaguya escaped from the emissaries and fled to Gensokyo. Taking refuge in an ancient manor called Eientei hidden deep within a secluded bamboo forest, the two Lunarians began a new exile. After several centuries of isolation, she was eventually reunited with Mokou, who had also used the Hourai Elixir to become immortal, and the two continued their feud, murdering each other on a nearly daily basis.
Later, Reisen Udongein Inaba had came to Eientei, explaining that she escaped from the Moon to Gensokyo and incidentally met her and Eirin, and that she would like to live with them in exchange for protection from the Lunarians. Kaguya, remembering of herself on her past, accepted Reisen's offer to live with them peacefully. It all changed when a war had erupted between the Lunarians and humans, where the moon rabbits had forced Reisen to come back and fight in the military. Reisen, who did not want this to happen, talked with Kaguya, to which Kaguya talked to Eirin on what to do.
During the events of Imperishable Night, Kaguya had been hidden in a secret pathway along with the true moon by Eirin to ensure any Lunarians sent to recover Reisen would not discover her. The heroines of Imperishable Night, however, did discover her, and challenged her to return the full moon to Gensokyo. After being defeated, Kaguya unleashed her powers of eternity in an all-out bid to break the spell of the Imperishable Night cast by the heroines. Finally, she relented and the true moon was recovered, leaving everyone bored on what to do. To appease their boredom, Kaguya invited the heroines to go on a "trial of guts" and exterminate her enemy, Fujiwara no Mokou.
- Eirin Yagokoro (Fellow Exile, Loyal Attendant): Kaguya is Eirin's friend and they have a long shared history. Eirin is extremely loyal to her, as seen when she willingly made the Hourai Elixir for Kaguya, killed emissaries and escaped to Earth with her.
- Reisen Udongein Inaba (Fellow Exile, Pet): By extension, Reisen is one of Kaguya's pets and Kaguya seems to have a friendly relationship with her, often making fun of her. Reisen had first met her and Eirin on coincidence, and asked for asylum due to her life under the Lunarians, which Kaguya had accepted.
- Tewi Inaba (Allied Earth rabbit): It is unknown what specific relationship they have, but technically under Eirin's extension, Tewi is loyal to Kaguya as well. Tewi had noticed Kaguya and Eirin in the Bamboo Forest of the Lost since their first few hundred years coming there. At some point, Tewi had made a deal with Eirin which she had accepted, so Tewi knows Kaguya due to Eirin's influence.
- Fujiwara no Mokou (Bitter enemy): Kaguya shares a mutual rivalry with Fujiwara no Mokou. They begun their rivalry when Mokou's father had proposed marriage to Kaguya, only for her to decline and tell him to find the Impossible Requests, which had embarrassed him and his family, causing Mokou to seek vengeance on Kaguya.
- Kaguya, and the whole of Imperishable Night, is inspired by the Japanese legend of the Moon Princess, also known as the The Tale of the Bamboo Cutter, sometimes called the legend of "Kaguya-hime" (Princess Kaguya).
- In Hirigana, her name is spelled as "ほうらいさん かぐや".
- Her first name "輝夜" Kaguya, means "shining night", "sparkling night", or "radiant night". "蓬莱山" Houraisan refers to "Mount Hourai". And indeed, to not only be able to find the location and survive the impossible perils of ascending Mount Hourai (a legendary place filled with powerful youkai, mountain men, and other supernatural beings of every kind), but to also be able to enjoy a beautiful evening there, likely with some traditional Moon Viewing, would be to experience a truly otherworldly beauty: a shining night on Mount Hourai.
- Contrast Kaguya's name with "咲夜 十六夜 (Sakuya Izayoi)", a character speculated to have unrevealed connections to the moon and to lunarians, whose name means "blossoming night" (Sakuya) and the "full moon on the sixteenth night of each lunar month" (Izayoi). They also both possess powers of time control.
- Mount Hourai is the name of a legendary mountain that floats above the sea. Its inhabitants were said to possess, among other treasures, the elixir of immortality. *It was also the destination of one of Kaguya-hime's impossible tasks.
- A silhouette of Kaguya occupies the front of Imperishable Night's jewel case.
- Also in Inaba of the Moon and Inaba of the Earth, she is depicted as a terrible cook, and as innocent and naive.
- Kaguya and Mokou fight to the death every chance they get. Their relationship has been characterized as a constant "Tom and Jerry" back and forth battle.
- However, in Inaba of the Moon and Inaba of the Earth, Kaguya and Mokou's relationship seems much more casual instead—though that might be due to the carefree attitude of the author...
- In more serious doujin works, Kaguya is often depicted as having been driven insane or mentally unhinged as a consequence of her long life and inability to die permanently. However, in official works, namely Perfect Memento in Strict Sense, Inaba of the Moon and Inaba of the Earth and Cage in Lunatic Runagate, she is described as having a more cheerful and pleasant, if somewhat ditzy, personality, who likes to tease Reisen just like all the cast of Eientei. These different characterizations may stem from a more literal interpretation of the title of Kaguya's theme music, "Lunatic Princess"; believing it to be descriptive of Kaguya herself rather than the music.
- Kaguya is also the name of a Japanese lunar-orbiting probe launched in September 2007 as part of Project SELENE to map the moon's surface. At the time of the launch, fanart depicting Kaguya being "sent back to the moon" aboard the satellite, usually against her will, was popular (one tribute video even superimposed her theme music over footage of the launch of the rocket). The same probe was later intentionally sent crashing into the moon, giving way to a new surge of fanart.
- It can be conjectured that Mokou and Kaguya's rivalry symbolizes for the cycle of the Sun and the Moon: Kaguya, the Lunar Princess, and Mokou, who uses as an in-game avatar a fire bird that strongly resembles a phoenix.
- Kaguya was planned to debut as a playable character in Hisoutensoku, but was scrapped from the lineup due to time constraints. ZUN stated in an interview that her moveset as initially designed would have been overpowered and unbalanced the game and there was not enough time to properly balance her strength against the other characters (ironically the same issue was encountered with Mokou, who was also intended to be playable in the game).
- She is one of the few characters that does not wear any type of headgear including hats, accessories, etc.