Reisen Udongein Inaba is a moon rabbit and a deserter from the Moon who now resides in Gensokyo, a fantastical land where she serves under Eirin Yagokoro and Kaguya Houraisan. Known for her crimson eyes, Reisen can induce hallucinations and manipulate waves, making her a formidable opponent. She is frequently depicted as calm and collected but also struggles with her identity and loyalty after leaving the Moon. In the Touhou Project series, Reisen plays a significant role as both a boss character and a protagonist, reflecting themes of rebellion and adaptation in a new world.