Shuichi is a member of the tennis club. Although there are only five members in total, he enjoys his school life with them. One day, the situation around him begins to change when Shuichi is injured in an accident. While Ai, one of the club members, takes good care of him, Mio, his younger sister, remains grumpy. Amidst such an unpleasant situation, a major accident occurs that changes everything...