Kasumi Yamamoto is 35 years old and has been married for nine years. She is a mother of one child. Perhaps thanks to her serious swimming stints as a student, she still maintains a toned, athletic body even after giving birth. The problem, however, is that her sexual desire remains as powerful as it was back then... During her active career, she was surrounded by men boasting of their physical strength, and had many opportunities to engage in physical battles, but now that she's a mother, that's no longer the case. Marital relations have become less enjoyable...