Since her father's affair was discovered, her mother, Rikako, had completely lost her spirit. Worried about Rikako, who was losing her vitality day by day, Katsu decided to take his father's place and protect her. The two of them ended up crossing the line into forbidden mother-son incest. Despite her hesitation, Rikako accepted Katsu, who was surprised by his incredible virility. No matter how many times he ejaculated, his erect penis remained hard. Each time he ejaculated inside her, Rikako's heart drifted further away from her husband...