Kazuki Shimada

Ishida's best friend in elementary school. He helped him bully Nishimiya. When Nishimiya moved away, Shimada placed all the blame on Ishida and soon became the ringleader of the people bullying Ishida: frequently stealing his shoes, beating him up, and writing threats and cruel things on his desk in chalk every morning. Ueno wants Ishida and Shimada to be friends again and gets Ishida to the amusement park were Shimada is now working, but Ishida storms away, deciding he does not care about Shimada and does not want to be his friend again. It is revealed that when Ishida falls while saving Nishimiya, Shimada sees him and saves him from the river; however, Ishida never learns this because he is unconscious at that time and Shimada asks Nishimiya, who witnesses the event, not to tell him about it. (Source: Wikipedia)