Hideki has just married his childhood friend Risa. They had planned to have a baby soon after the wedding, but Risa got pregnant soon after. Hideki's plans were completely ruined. Risa lost all sexual desire after getting pregnant, and the couple has completely banned sex. Hideki's balls are on the verge of exploding, but he has no choice but to live a lonely life masturbating to adult videos. Then, one day, his sister-in-law Rin comes to help with the housework.