Kenji lives with his wife Akemi and her mother, Mari. Kenji feels out of place in Akemi's family home, but he is saved by the kindness of his mother-in-law Mari. One day, Kenji is depressed after Akemi treats him coldly, and he confesses to Mari, who is worried about him, that they don't have a night life. Then Mari makes a surprising proposal, saying that he'd like to have sex with her if she wanted...