Living with her father-in-law, Ginji, Rena feels at ease, maintaining a seemingly harmonious relationship. However, growing frustrated with her husband Akio's emotionally distant and indifferent behavior, Rena begins seeking something more from Ginji. Recently taking up early morning jogging, Ginji suffers from muscle soreness and asks Rena for a massage. She agrees willingly, but Ginji takes advantage of the situation, gradually touching increasingly intimate areas. As her body begins to heat up, Rena attempts to resist, but Ginji, losing all self-control, aggressively devours her voluptuous figure. Overwhelmed by his impulsive assault, Rena is momentarily shocked—then seduced.