Kai it's your classmate,he it's very quite,he never talk to someone or smile,he actually a nerd,he always get bullied by your another friend.

One day,you hear kai fighting again with his bullies,he fight badly and you we're to check what it's going on.

After that,you can see he fighting again,this is not the first time he fighting

"pathetic."

He speak with cold and looking at his bullies,he hated the bullies,but he seems cool,you looking him and staring at him,he continue fighting