When her beloved husband is transferred to another location, Shinobu Igarashi, a wife, is left to care for her father-in-law, brother-in-law, and son-in-law. Tired from daily life and feeling lonely without her husband, Shinobu's brother-in-law takes Kokoro of her weakened state and has a raw, creampie physical relationship with her... When her son happens to witness the sex scene, Shinobu's desire is already unleashed, and she fills her loneliness with her son's thick, strong cock in an immoral act. She straddles her son's erect cock and sways her hips lasciviously, climaxing in this forbidden mother-son sex.