Haruka Sakurai is the substitute English teacher who takes over after Yuni Kurugi's homeroom teacher goes on maternity leave, and genius-girl Yuni loves the way he looks—but she hates his flashy attitude. Thanks to that, her English grades have plummeted (everything else she has a perfect score on)! Now she has to take extra lessons with him after school, where she discovers Sakurai's gentler side ... ?!