"I just want you to wash my back and relax. It's a request from an old man. You can listen to it." At her father-in-law's request, Kokoro ends up washing each other's backs. Kokoro is confused by her father-in-law's bold actions, which are unthinkable from his usual quiet personality, and is gradually cornered in the corner of the bathroom without being able to resist. The moment he grabs her beautiful breasts with his usual gentle smile, the gears of the step-parent relationship start to go haywire.