Touhou Game Club

# Because she has spent a thousand years hiding inside Eientei, Kaguya is often depicted in fanworks as a recluse or even a hikikomori who shuns outside interaction (which is not entirely accurate). In humorous works, she is often portrayed as being a NEET, or unemployed geek, who sits at home and surfs the Internet all day.

# In contrast to above, her portrayal in Inaba of the Moon and Inaba of the Earth shows her as a sheltered person who wants to explore the world outside of Eientei.

# 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 "[ur;=http://en.touhouwiki.net/wiki/Kaguya-hime]Kaguya-hime[/url]" (Princess Kaguya).

# 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.

# Popular nicknames for Kaguya among her fans in Japan are "Teruyo", which is a deliberate mispronunciation of the kanji in her name, and 「ぐや」 ("guya") which is an unusual abbreviation of her first name, ommiting "ka."

# 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...

# Kaguya's appearance closely resembles that of Hazuki, the cat-ear-wearing vampire girl from the anime Moon Phase. Because of this, Kaguya is often depicted with cat ears, either real or fake, on her head, even occasionally uttering lines from the anime's opening song, "Neko Mimi Mode". The cat-and-mouse dynamic between her and Mokou adds another layer to this depiction.

# 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.

# 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. (Example)

# Since she is generally acknowledged to be easier than Remilia, Yuyuko and sometimes even her servant Eirin, Kaguya is thought rather weak for a final boss (although most bosses in Imperishable Night are considered easier than those in earlier games, and continues are not allowed against Kaguya, unlike the previous two). As a result, fanworks often depict her as being completely helpless and dependent on Eirin to survive, and her theme song's climactic passage has had the words "Eirin, Eirin, tasukete Eirin!" (Eirin, Eirin, help me Eirin!) set to it by the fans. However, Kaguya has a larger spellcard arsenal than either Remilia or Yuyuko and attacks confidently and without hesitation in the actual game. In addition, considering she was scrapped from Touhou Hisoutensoku for being overpowered, Kaguya being weaker than other bosses might not necessarily be true. Indeed, if one takes the Final A route in Imperishable Night, it is actually Kaguya who aids Eirin for Eirin's final spell card.

# 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).