Fault!!

Shuichi belongs to the tennis club. There are just five members in total, but he enjoys his school life using them. Some day, the problem around him starts changing when Shuichi gets injured in the accident. While Ai, one of several members, requires a good care of him, Mio, his younger sister, stays grumpy. In such an unpleasant situation, a big accident happens which changes the whole situation...