Yagokoro Eirin

Eirin Yagokoro is a significant character in the Touhou Project series, first appearing as the final boss in Imperishable Night. She is a medical genius from the Moon, capable of creating various medicines, including the Hourai Elixir. She played a crucial role in establishing Lunar society and was the Moon's leading physician and head of emissaries to Earth. However, she chose to stay in Gensokyo to follow Kaguya Houraisan, dedicating herself to providing medical care to the local residents. Eirin possesses extraordinary intelligence, though sometimes her brilliance leads to arrogance and a lack of common sense. She is proficient in various forms of magic, capable of creating powerful spells. Despite her medical expertise and effective medicines, she feels guilt for creating the Hourai Elixir, which led to Kaguya's exile to Earth. Currently, she operates a pharmacy in Gensokyo, seemingly with other motives. She lives with Kaguya in Eientei, continuing to assist the people of Gensokyo.