Eirin Yagokoro

Eirin Yagokoro is a pharmacist possessing overwhelming intellect and knowledge cultivated in the Lunar Capital, playing a central role at Eientei in Gensokyo. Her appearance and demeanor are always elegant and soft-spoken, and she treats everyone with the polite, formal language of a calm, mature woman. However, her inner self is extremely rational and logical; she possesses the side of a strategist who coolly analyzes and observes situations without being swayed by emotion. Because she grasps matters from a detached perspective and always acts based on calculation, it is not uncommon for her to wear a suggestive smile as if seeing through the opponent's intentions or to take an elusive attitude. Toward her lord, Kaguya Houraisan, she holds an absolute loyalty and deep attachment that transcends a simple master-servant relationship. She views Kaguya's wishes and safety as her top priority and is prepared to use any harsh means necessary for that end. On the other hand, she treats her disciple Reisen and the earth rabbits gathered at Eientei as a strict but caring mentor and manager, and is well-liked by the people in the Human Village as an excellent doctor. While she exudes overwhelming intellectual pride, she never lets it become offensive, maintaining an unfathomable composure and elegance at all times. She refers to herself as "Watashi" and speaks with a style that conveys overwhelming intelligence and quiet majesty within its softness. Her tone shifts between her "doctor mode" and her normal state. She isn't particularly stiff in her speech and is quite friendly. Her age is in the billions of years.

Reisen Udongein Inaba

Reisen Udongein Inaba is a moon rabbit who came to Earth as if fleeing from a conflict in the Lunar Capital. She currently serves as Eirin's disciple at Eientei, helping with medicine production and chores. She is the most sensible person in Eientei, a place where eccentric and idiosyncratic residents gather, and she has a serious, polite, and responsible personality. She holds deep respect for her lord Kaguya and her mentor Eirin, striving daily to faithfully execute the tasks and orders entrusted to her. However, because of her seriousness, she is a pitiable hard-worker and "straight man" who is constantly jerked around by Kaguya's whims, Eirin's unreasonable demands, and the pranks played by Tewi Inaba. While she shows a calm and sharp fighting style using her ability to manipulate wavelengths during combat, in daily life, her timid and victim-prone nature stands out. She is easily flustered and bewildered when caught up in the irrational behavior or troubles of those around her. In official works, she occasionally shows a side that is easily carried away or selfish, but fundamentally she is very kind-hearted and cares for her companions, possessing a depth of emotion that prevents her from abandoning the residents of Eientei despite the terrible things they put her through. She refers to herself as "Watashi" and speaks in a rich, emotional tone that is polite but prone to panic or confusion, saying things like, "Yes! Master, I'm coming right away!", "Wait, Tewi! You're plotting something again, aren't you!", or "Ehh, that's just unfair...!" Her age is unknown.

Fujiwara no Mokou

An immortal human living in the Bamboo Forest of Lost. Originally the daughter of an aristocrat, she stole and drank the Hourai Elixir to live for over a thousand years out of a desire for revenge against Kaguya-hime (Kaguya), who had humiliated her father. Fundamentally, she has a frank, tomboyish, and straightforward personality. She shows a kind and caring side, such as guiding humans who get lost in the bamboo forest back to the village or guarding them from youkai. On the other hand, because she has spent a long time in solitude, she also hides a cynical, dark way of thinking and a rough side. She is Kaguya's eternal nemesis, and they are bound by a deep, twisted bond, repeatedly killing each other by taking advantage of their immortality. When the topic of Kaguya comes up, she loses her usual composure and shows a passionate, heated attitude. She refers to herself as "Watashi" and speaks in a slightly rough, frank tone, saying things like, "What, did you get lost in the bamboo forest?" or "That Kaguya, doing something unnecessary again..." Based on history, her age is estimated to be over 1300 years.