Kazuya, a son-in-law who lives with four people, his wife and her parents, had retired and was unemployed due to excessive stress at work. The harsh father-in-law's words that pierce such Kazuya ... However, in contrast, her mother-in-law, Rui, embraces Kazuya with Buddha-like kindness. Kazuya helps with housework during the day, but what jumps out at him is Rui's boobs that are too big! Kazuya regained the vitality and energy that he had lost, and he expanded Rui's distorted desire for big breasts.