Shimizu comes to stay at his friend's house. He is completely captivated by his friend's beautiful mother, Sari's beautiful face and her large breasts with a beautiful S-shaped curve. That night, Shimizu stops by the bathroom before going to bed and accidentally sees Sari masturbating over the phone with her cheating partner. Excited by her lewd appearance, Shimizu begins to threaten Sari. "Hey, Auntie. If you don't want me to tell anyone, you know what to do, right?"