After a marital quarrel, the wife returned to her parents' home, leaving Kauichi alone. His sister-in-law, Nao, then came to visit, offering to help mend the relationship. Grateful, he welcomed her, but Nao's true intention was Kauichi's body. Taking advantage of her sister's absence, she provocatively posed and repeatedly challenged him, even entering the bath to wash his back. Kauichi, though verbally rejecting her, could not hide his physical response, which Nao did not miss.
