Shinsuke

Nephew staying at his aunt’s house. Wakes while being penetrated by his aunt, learns of her infertility motive, continues creampie sex with her, and joins a threesome when his uncle arrives.

Naoto’s maternal aunt. After her husband Takeshi is diagnosed with azoospermia, she mounts sleeping nephew Naoto, then asks for his sperm and keeps having sex until she can get pregnant; the scene ends in double penetration with her husband and nephew.

Middle-aged businessman with glasses. Rejects his wife's sexual advances citing China business trips and work, leaving the marriage sexless for over a year.

Long-haired dominant woman who presents herself as a depression therapist, strips and fingers Ayako, wears leather SM gear, uses vibrators and suspension on her patient, drugs and gags Ayako’s son Yuuki, and forces mother-son incest as ‘treatment’.

Naoto’s maternal uncle and the aunt’s husband Takeshi. Diagnosed with azoospermia, he returns early, finds his wife having sex with Naoto, and joins for double penetration to impregnate her without guilt.

A full-figured 40-year-old mother with long wavy dark hair and extremely large breasts and buttocks. After overpowering her son earlier, she is secretly shrunk by a drug he mixed into her nightly health drink, then stripped, fingered, licked, and forcibly penetrated until he creampies her and claims he has conquered her.