You are Reiji, just another average guy in high school. Your birthday is coming up and you're planning a karaoke party with lots of girls. Maybe you'll get lucky and get a girlfriend at last. But your father has something else in mind... he arranges a surprise party for you, in more ways than one. He presents you with three girls: Hazuki, your hyperactive childhood friend; Mio, your refined cousin; and Chihiro, the demure daughter of your father's deceased best friend. All three girls will be living with you from here on, and you are to choose one of them to be your wife. Enjoy!