It's been a while since she had sex with her husband... but she wants to have a child, so her father-in-law suggests, "I'll stimulate him, so why don't we work together?" She plans to play pranks on her husband to make him jealous. But when she gets started, her husband doesn't react! Her father-in-law's sexual harassment only gets more intense, and he ends up forcing his penis into her in front of her husband! Yumika then gets aroused by her actions with her father-in-law, and ends up becoming a lover with her father-in-law, who was her caregiver. Yumika, who is addicted to intense sex with the old man, begs her father-in-law to help her conceive.