Satsuki Kuriyama discovered her boyfriend having passionate sex with her mother after secretly checking his phone. (KEED-86)

Caiyue's daughter got a boyfriend, and as a mother, she blessed her daughter. However, as her daughter's boyfriend visited frequently, Caiyue developed impure feelings for him and eventually had a sexual relationship with him. Caiyue was tormented by guilt towards her daughter, but her instincts craved a penis. Caiyue's heart wavered between motherhood and womanhood. She wanted to end the relationship for her daughter's sake, but her obsession with a penis made it impossible for her to break free from this illicit affair.