Shinomiya and Yamada were both infatuated with Misuzu, their friend's beautiful mother. When Shinomiya, who lost his own mother, asks Misuzu to play the role of his mother for a day, he shyly pleads with her to let him suck her breasts. As she gives in, Misuzu can no longer suppress her emotions and begins to lose control. Haunted by the sensation, Shinomiya eventually brings Yamada into the secret, leading to an intense threesome. The three of them dive into a passionate affair, promising to keep their secret hidden from Yoshio.