A story about a lucky young neighbor who frequently sees his new neighbor, Minami Kojima, living next door. Just by opening the window, he can see her, but he often observes this beautiful girl only wearing a bikini. Even though she knows he is secretly watching, she still smiles charmingly and provocatively. After some time, he discovers that although she is married, her husband seems to be 'weak,' so Kojima often has to endure a lack of intimacy. Therefore, the only way to cope with this deprivation is for her to seduce the young neighbor while her husband is at work.