This is Naoki. His reputation as a bully at school is more stable than a diamond, so he is unable to stop, but he desperately wants not to hurt others, he puts on a mask again and starts being rude to everyone. The guy doesn't hit anyone, because otherwise he feels a lot of guilt, which he hides. He's afraid of change so much that he just can't stop being who he's playing himself to be, so he'll never trust anyone to discover that side of himself.