Hell Girl - Season 3 Episode 4

Yukawa is constantly bullied by his classmates until one day, he is saved by a stranger named Nishida Shin who knows Kendo. Nishida begins teaching him Kendo, causing him to become more active, outgoing, happy, and cool. He is also no longer bullied. However, one day aboard a bus, a deranged man begins threatening another man for staring at him, cutting the other man's hair off and dragging him off the bus. Yukawa's image of his hero is shattered when Nishida fails to intervene, supposedly afraid of putting Yukawa in harm's way. He sends Nishida to Hell. Feeling the world cannot change even if he himself changes, Yukawa quits Kendo and reverts to his former timid self.