The "Brain of the Moon". Secondary final boss of Touhou's Imperishable Night.
Lunarian pharmaceutical genius responsible for creating the Hourai Elixir that gave her good friend Houraisan Kaguya - and later Kaguya's bitter nemesis, Fujiwara no Mokou - immortality. She has since been Kaguya's bodyguard and caretaker in their mansion, Eientei. She is also the mentor of Kaguya's pet lunar rabbit, Reisen Udongein Inaba, and by extension Reisen's charge, earth-born rabbit youkai Inaba Tewi. Owing to her expertise, she became Gensoukyou's chief pharmacist.
Due to her estimated age (well over 1000 years old and possibly one of the original Lunarians) and her relatively mature demeanor (compared to her charge), she is often included in the "Old Maids Alliance" with Yakumo Yukari and Yasaka Kanako.
Most famous for the fans' rallying cry "Eirin! Eirin! Tasukete Eirin!" which, in fact, originated from Houraisan Kaguya.
Her surname invokes the name of the Shinto god of intellect and wisdom, Yagokoro-no-Omoikane. This, combined with ZUN's comment about her being in "the higher order of gods", gave rise to rumors that she may in fact be Omoikane.
Person: long hair, silver hair, braid, single braid, bangs, grey eyes, black eyes, blue eyes
Outfit: multicolored dress, blue dress, red dress, collared dress, constellation print, trigram, petticoat, frilled dress, puffy short sleeves, short sleeves, white sash, sash, socks, white legwear, shoes, black footwear
Accessories: nurse cap, blue hat, red cross, bow (weapon), arrow, white bow
- "Yagokoro", a horribly failed attempt to draw her on Shift_JIS