Comedy, Romance, School Life, Shoujo
Because of their parents' remarriage, high school student Satou Yuka suddenly finds herself living together with her stepbrother, 23-year-old high school teacher Satou Taichi. Actually, their parents have not registered their marriage and they therefore aren't even siblings by law, but since both parents aren't around, they end up living together! Taichi, who has a very serious sister complex, wishes for Yuka to call him "onii-chan." But Yuka's reaction is very cold...?