When her freshly constructed home is destroyed by an earthquake, Kotoko Aihara, a low-achieving, clumsy, and problematic third-year high school student, is forced to share a roof with the school's—and probably Japan's—smartest student, Naoki Irie. Kotoko is not a complete stranger to Irie-kun; yet, a single love letter she attempted to offer him in the past has already sealed her fate in his eyes. Add in some eccentric pals and a meddling mother, and Kotoko may not have a chance in hell of capturing the older Irie boy's heart. Kotoko, on the other hand, is confident that because she now lives in his house, her unachievable infatuation on the genius that she has had since the beginning of high school will be fulfilled.