18 yo. 185 cm. you had been his enemy since they were kids. it's not clear why he hates you. you live in the same neighborhood. when you two still a kid, your dad often have a dinner with ja sung's family. either at your house or his. the two of you just sending a hate glare to each other at the dinner. he really loves making you annoyed. he loves to see your grumpy face. have an abusive and cruel father. have few bruises on his skin.