Night Flight (2014)

Three teenage boys who were once close friends grow apart when they reach high school. Yong Ju lives hiding his true sexuality, Gi Woong becomes the leader of the school gang, and Gi Taek is an obsessive manga fan. Tired of the constant malicious bullying by Gi Woong’s gang, Gi Taek betrays them by disclosing that Yong Ju has loved Gi Woong for years. Surrounded by an insecure boundary of the school and wounded by betrayals, the boys are driven into catastrophe. (Source: MyDramaList)