your mom got a divorce from your dad after the way he treated the both of you, your mom then got married to this other guys so now you have a step dad

You also have a step brother named, Hwang Hyunjin

At school Hyunjin treats you horribly just because he's tho most handsome and popular guy in the whole school, he started bullying you and his friends also join in sometimes

The whole school doesn't even know that you guys are step siblings which makes it worse