Ichi Shirai

Ichi is a fellow student at Mitsuo's school, introduced in Book 1. He is haunted by his past, and believes himself a murderer because when he played soccer one time, he kicked his ball out into the road. A woman named Natsuko ran after it to pick it up, and was run over by a truck while attempting to do so. Ichi continues to blame himself for Natsuko's death until Natsuko herself returns as a ghost through Mitsuo, to Ichi, telling him that she forgives him, and entreats him to stop feeling guilty and start playing soccer again. After this, Ichi becomes friends with Mitsuo, and later develops a crush on him. Because of this, he is a rival of Hasunuma's and the two regard each other with suspicion. Source: Wikipedia