While his wife was away on a two-day trip with a friend, Kenji was enjoying living alone, watching the adult videos he had hidden away as a stimulant. However, excited by the freedom he hadn't had in a long time, he accidentally forgot to lock the front door. Then, at an unfortunate time, his sister-in-law Reiko came to visit. Suspicious of the unlocked front door, Reiko went into the house looking for Kenji... and she came across Kenji, who was masturbating engrossed in his thoughts...