“I only want to wash your back and help you relax. Humor an old man’s request, won’t you?” At her father-in-law’s insistence, Koharu agrees to wash each other’s backs. Stunned by behavior so bold and unlike his usually quiet manner, she cannot bring herself to resist strongly and is gradually cornered in the bathroom. The moment he grabs her beautifully shaped breasts while wearing his familiar gentle smile, the relationship between the two adult in-law role-play characters begins to go horribly wrong.