Eirin Yagokoro  

, 八意 永琳

The term "Yagokoro" translates to "Eight Minds," while "Eirin" means "Eternal Jewel." Eirin was a brilliant pharmacist who lived on the moon, and she had once been persuaded by Kaguya to create the forbidden Hourai Elixir. After consuming it herself, Kaguya was discovered, and only she was punished, leaving Eirin feeling guilty about what happened. Later, the moon court pardoned Kaguyas sins and summoned her back. However, when Eirin attempted to retrieve her from Earth, she learned that Kaguya did not wish to return to the moon. Driven by her past guilt, Eirin betrayed and murdered all of the other emissaries who had been sent with her, in front of the eyes of the earthlings who had nurtured Kaguya. In order to keep them silent, she bribed them with the Hourai Elixir and went into hiding with Kaguya in Gensokyo.