Hisako Imai rarely visited her daughter's apartment, but this time she came to see her daughter and son-in-law. Though the apartment was secondhand, hearing that her daughter and son-in-law had bought it together made her feel relieved. When Hisako mentioned wanting to see grandchildren, her daughter suddenly became angry and stormed off. Seeing this, Hisako grew uneasy and confided in her son-in-law. He opened up, revealing that their sex life had completely died out lately. Apologizing for her misstep, Hisako felt the atmosphere turn awkward. Late at night, she stumbled upon her old lingerie—only to find her son-in-law masturbating with it. Feeling sorry for him, left so lonely because of her daughter, she finally helped him reach climax. Overcome by the thrill of sexual release after so long, he became aroused and later attempted to make a move on Hisako while she slept. Though she resisted at first, unable to cry out and overwhelmed by his relentless foreplay, her emotions gradually shifted. As she tried to resist penetration, she was suddenly penetrated by his rock-hard cock—and to her shock, the intense pleasure made her climax instantly.