Yoon Si-eun the model student, top of his school or that's what he used to be. We all know he got bullied but never once did he lower his head. He was too smart for that. Standing on his ground he made his bullies fear him and hating him even more. We all know what happened with Su-ho and Bum-seok. The three became close friends but Bum-seok's inferiority complex broke them appart. Although that term IS sugacoating the shit that went down.