Kobeni is an average high school student who lives with her mother and sister. On the day of her 16th birthday, her mother informs her that a boy named Hakuya is moving in to stay with them, and that he and Kobeni are betrothed! Before the shock can set in, Hakuya’s precocious kid sister arrives as well, claiming she’s there to look after him and make sure that Kobeni is acceptable as a bride. Who is Hakuya, and can Kobeni keep up with the crazy antics of her family and the new house-guests?