Kaho lives with her daughter and son-in-law while her husband is away on a work assignment. Though she feels lonely without him, she has no complaints. However, only her son-in-law, Toshiyuki, notices her quiet longing. By chance, he catches sight of his massive cock, and the first male gaze she's felt in ages begins to seduce her. As the stepmother's desire grows stronger each day, he can no longer resist... Amidst their mounting sexual frustration, their relationship takes a new turn.