Sent to Tokyo for training, Katayama ends up staying at his department chief's house. That night, while he is asleep in his futon, the chief's elder daughter, Yoshie, sneaks into his room and seduces him, resulting in an internal ejaculation. The next morning, upon waking, Katayama discovers the younger daughter, Kozue, masturbating in the living room. Unexpected events continue to unfold.