Katsuno is a widow living in an old Japanese house. Once known as the head of the "Ura-Nishimoto-ryu" school, she has long upheld the dignified role of a traditional housewife. Dressed in kimono, she exudes the grace of a bygone era. Her son, Shuichi, returns home for a visit. Katsuno summons him to her room, inviting him to share a special moment. As the rightful heir to the Ura-Nishimoto-ryu, Shuichi is still a virgin and must undergo a sacred ritual performed exclusively by his own mother to master the ultimate technique: "Female Body Landscape." Katsuno serves as the guardian of this ritual, playing a crucial role in Shuichi's coming of age.