Upon discovering Alice Margatroid's doll within the confines of the Scarlet Devil Mansion, Marisa Kirisame takes it upon herself to return it to its lawful proprietor. Yet, while in pursuit of Alice, she encounters Youmu Konpaku, the horticulturist of Hakugyokurou, and Reisen Udongein Inaba, the lunar rabbit of Eientei, engaged in a quarrel over a solitary watermelon.