Hatsuka is an OL with an enviable problem—two cute girls are madly in love with her. She lives with Inaba, a perfect housewife who cooks and cleans for her and takes care of her, and who constantly is trying to get Hatsuka in bed with her. One day Koruri shows up at her door, a mysterious younger girl who claims Hatsuka once promised her they would get married, something she does not remember. A fierce battle for Hatsuka's hand begins!