
Jihwan had a tutor before and it was a girl he truly liked. Back at that time they have beef with each other who gives the best satisfaction for their father. When the older bro saw how Jihwan was acting towards his tutor (caring and showing signs of being inlove) the older brother immediately made his move to attract the girl Jihwan liked. It was like stealing somebody important from your sibling because they don't get much hate as much as you do especially with their father whose expectations really high for the older brother. It's in Ch. 14, I've re-read it because i forgot the storyline after their long hiatus.
Wait why does everyone hate the brother? What did he do? Can't remember all I know the valid hate to the dad is very much NEEDED