Main Profile編集



八意 永琳(やごころ えいりん)

Eirin Yagokoro




Can create all types of medicine, genius-level intelligence.


Unknown, but is of an incredible age ("much older" than 1400+-year-old Kaguya, was instrumental in the establishment of the lunar capital.)






  • Dark grey eyes, long silver hair, has a large braid on her back, and carries a strange pair of bow and arrow. Her clothing is red and blue, and is covered with constellation patterns. She also wears something similar to a nurse's cap.





Eirin is a genius of medicine from the Moon, able to create even the Elixir of Immortality. She is living in exile in Gensokyo after choosing to stay with and devote herself to Kaguya Houraisan on Earth rather than take her back to the Moon. She was a very well-known figure on the Moon, having not only been instrumental in the founding of Lunar society with Lord Tsukuyomi, but also being its leading medical mind and the person in charge of the Moon's emissaries to the Earth.

During the events of Imperishable Night Eirin attempted to seal the passage between the Earth and Moon, which becomes open during full moons, by casting a spell that would seal the Earth inside a chamber (similar to a Chinese folktale about a paradise found inside a pot). She only meant to do this to protect both Kaguya and Reisen so that the emissaries coming from the Moon wouldn't be able to reach them, but this did not go unnoticed by the various Youkai in Gensokyo who enjoy the moonlight.

It seems that now Eirin has begun using her knowledge of medicine to act as Gensokyo's premier pharmacist, selling medicines at Eientei ranging from sleep aids to various cures. She is generally a fairly pleasant person and is devoted to serving her best friend, Kaguya, but she does not suffer fools gladly, and because of her incredibly high intelligence, she can come across as conceited, impatient and condescending at times to those not sharp enough to follow her explanations immediately.

Fun Facts編集

  • The characters for Yagokoro literally mean "Eight minds", and Eirin "Eternal jewel". "Eight" is the sacred number especially for ancient Japanese, and it could mean "sacred, numerous, infinite". For example, Yakumo (八雲, eight clouds), Yashima (八島, eight islands), Yata no Kagami, Yaoyorozu no Kami. And gokoro is an ancient reading for 意, which could indicate something about heart or mind. So her whole name could mean "Intelligence of eternally clear brightness over infinitely extended area", referring her to be the "Mind of God".
  • Eirin's clothing has trigrams (broken and solid Yin/Yang lines) lining the bottom hem. They appear to be the complete set of trigrams used in Feng Shui, and match the set of trigrams on the Hakkero.
  • Although Eirin was the one who formulated the Hourai Elixir, it has never been explicitly stated whether she has consumed it herself or not. Her official profiles say nothing on the matter, and she never claims in-game that she is immortal, unlike Kaguya (who refers to herself as an eternal being) and Mokou (who flatly states she is immortal). Considering that she was punished far less severely than Kaguya was, it is possible that leniency was granted in consideration that she did not actually drink the elixir. While she is incredibly old, Lunarians do not die of natural causes. (She does acknowledge that she has prolonged her life through the use of drugs, but does not specifically mention the elixir; also, Yuyuko mentions her power of death will not work on Kaguya or Mokou, but offers no such caveat against Eirin.)
    • Additionally, Eirin has actually entered the Netherworld. Mokou apparently cannot.
  • Eirin has a Spell Card named "Apollo 13" after the aborted third American moon mission launched in April 1970. The spell card's spell sign is "Curse of the Heavens", and seems to imply that it was Lunarian magic, not mechanical failure, that critically damaged the spacecraft and forced it to abandon its lunar landing so as to forestall the "invasion". It's also stated that the Lunarians know why the number 13 is cursed. Could Eirin have something to do with it?
  • Eirin is often shown in fan works as using the many rabbits at Eientei, especially Reisen, as test subjects for various drugs and medicines. And according to Cage in Lunatic Runagate, she actually does sneakily give medicine to the rabbits.
  • Eirin is often placed as doctor or nurse in fan works by obvious reasons.
  • Eirin's Last Spell (Forbidden Arcanum "Hourai Elixir") is the only spell card that is shared by two characters (the other character being Kaguya Houraisan) in the whole Touhou series.
  • She might be based on Ame no Yagokoro Omoikane no Mikoto (天八意思兼命), the god who thought of the plan to lure Amaterasu out of hiding. This can be seen by her spell card, and by the correlation between Eirin's sharp intellect and Omoikane's. (Takami-Musubi is also very strongly associated with intellectual facilities.) The interrelationships of various lunar figures presents a more interesting situation. Eirin is distantly related to the Watatsuki sisters, both based on mythology. In Cage in Lunatic Runagate: Chapter 3, Watatsuki no Toyohime mentions that Eirin's participation was critical to the founding of the lunar capital, and that she was older even than Tsukuyomi. Omoikane is the son of Takami-Musubi, one of the great gods that summoned Izanagi and Izanami into existence, but it's unclear whether Omoikane was born before the creation of the Japanese islands, which also saw the births of Amaterasu, Tsukuyomi, and Susanoo. Regardless of whether she is "meant to be" Omoikane, Eirin clearly draws on Omoikane in many ways.
  • Eirin had recently developed a medicine called Kochoumugan (Butterfly Dream Pill), which guarantees the person who takes it will have a pleasant dream once they fall asleep. The medicine was featured in an article in the Bunbunmaru Newspaper, but still remains fairly unpopular (mostly due to the fact that the paper itself isn't too popular). There is one customer, Alice Margatroid, who has returned numerous times to purchase the medicine however, although the reasons why were never disclosed.
  • In Inaba of the Moon and Inaba of the Earth Chapter 13, it is seen that Eirin wants to dissect and/or experiment on Suwako Moriya due to her similarities to a frog.
  • In Tibetan Buddhism, the bow held in the right hand with an arrow in the left (as Eirin holds them) is a symbol of wisdom as a means of projecting method or skillful means.
  • She is often grouped with Yukari Yakumo and Kanako Yasaka among the fandom, because their names contain the character 八(which is sometimes read as 'ya'), which when misread, means old hag.
  • Eirin is sometimes parodied standing in a pose similar to G Gundam character Master Asia due to their similar hair styles and color. This could also be a reference due to the fact that Master Asia is refereed to as "Tohofuhai"(東方不敗) "The Undefeated of the East".
  • The bow and the arrow are a possible reference to the huntress greek moon goddess Artemis (sister of Apollo; In Imperishable Night, ZUN made a joke about Apollo being the sun god, so he surely knows about Artemis). Artemis (or her bow) sometimes represents the crescent moon, symbol of full maturity in the cycle of life (it suits Eirin very well).
    • Artemis is often assimilated to Selene (the personification of the moon), which is the root of Selenium, a non-metal antioxidant sometimes used as a medicine but toxic in large quantity to human beings. Antioxidants are known to improve life expectancy.
    • Ursa Major, one of the constellations on Eirin's clothes, was originally Callisto, a servant of Artemis.

Official Profiles編集

Imperishable Night - キャラ設定.txt編集


 ○6面ボス 月の頭脳=

  八意 永琳(やごころ えいりん)

  Eirin Yagokoro



















Stage 6 Boss, Brain of the Moon

Eirin Yagokoro

Species: Lunarian

Abilities: Creation of any kind of medicine; natural genius

She's a person from the moon. That means she's an alien. She has lived on the Earth for a long time. Her relationship with Kaguya dates back to their days on the moon.

The Yagokoro family is a line of medicinal geniuses that have been living on the moon for some time. Even among them, Eirin is exceptionally intelligent. She is much smarter than humans, which makes her rarely understood.

In truth, she has power well beyond that of Kaguya's. She saves her power and maintains it at a lower level out of respect for Kaguya.

Long ago, Eirin was one of a party of messengers who were sent to bring Kaguya back to the moon; the crime for which she was exiled to Earth had been forgiven. For some reason, she helped Kaguya kill all the other messengers instead. To ensure that the earthlings who lived with Kaguya would remain silent, she bribed them with the Hourai Elixir. The elixir had the power to make people immortal. None of those earthlings consumed the elixir, however, and died shortly afterwards.

It was later discovered that they were murdered.

More detail is available in Kaguya's profile.

Eirin is very surprised to see Sakuya, but only Eirin knows the reason why.

Book Synopsis編集

Bohemian Archive in Japanese Red編集

Main article: Article and Interview: Eirin

Eirin has created a new medicine called the Kochoumugan (Butterfly Dream Pill), which guarantees that one will have a pleasant dream. She says that since the youkai of Gensokyo rarely suffer from physical ailments, she began developing medicine for spiritual ailments instead. This particular medicine is ancient, but humans who took it in the past often found their dreams too enjoyable and never returned from the dream world, so Eirin has weakened its potency and made it safe to use. She also has a variety which causes nightmares instead of pleasant dreams.

In the interview, Eirin remarks that only a few people have come to buy the pill, even though it was a featured article in Aya's newspaper. Aya admits she doesn't have many readers. She is curious who is buying the medicine; Eirin is initially reluctant to say, but then reveals that it was Alice Margatroid. Aya mentions that she tried the pill herself, but found the dream uninteresting. Eirin suggests that she try Kochoumugan Nightmare Type (a scene in Shoot the Bullet).

Perfect Memento in Strict Sense編集

PMiSS eirin
Main article: Perfect Memento: Eirin Yagokoro
  • Eirin is the Lunarian pharmacist for both humans and youkai, a business she only started recently.
  • Her medicines are offered by consignment and direct sale, an ingenious plan to decrease her workload, as it provides each household a supply of medicine.
  • Although her medicines are well known to work with no side effects, youkai medicine and human medicine must never be mixed together.
  • It is said that you can visit her like you visit a normal doctor, and that she can even prescribe medicine for obscure illnesses.
  • The medicine is not only effective, but fairly priced.
  • Eirin is not fussy about payment; she will most likely wait until you pay her.
  • It is believed that Eirin has another reason for starting this business, as she began it suddenly with no motivation for profit.
  • Eirin is an enigmatic person surrounded by many mysteries.
  • However, she seems to lack general common sense, most likely due to her not living with humans.
  • Her answers regarding the mysteries about her are incoherent replies.
  • It's reasonable to believe her medicines come from the Moon or are developed with Lunar technology.

The Grimoire of Marisa編集

Main article: The Grimoire of Marisa: Eirin Yagokoro's Spell Cards
  • Insert Summary Here