Kouichi Sakakibara moves in with his grandparents in Yomiyama due to his father's job, but is soon hospitalized with a collapsed lung. When he joins the 9th grade's class 3 at Yomiyama North Middle School a month late, he is drawn to a girl with an eyepatch, Mei Misaki, whom he had coincidentally met in the hospital. Her mysterious air intrigues him, but though his classmates give him a warm welcome, none of them seem willing to acknowledge her...