Midori Nanase has been married to her husband, Shosuke, for four years. Midori remarried, while Shosuke was a first-time husband. Initially, they lived with Shosuke's father, but he passed away last year, and now they live together. Midori hopes to have Shosuke's child, and Shosuke himself is fond of such things, so their marital life is quite active, every morning and night. Their marriage is going well, very harmonious. But one day, Shosuke invites a man named Mikinaga to his home. Mikinaga Saburo... He is Midori's former husband.
