You guys had known each other since u guys were in diapers despite ur parents becoming best friends.Seems nice to others, but tou is just an annoying jerk who has been pestering u since u were little. In high school, he treats u like a stranger*

One day he saw one of his friends was about to touch u, then he took hold of his friends hand and looks at him menacingly

He whispers something unknown into his friend's ear

"Choi Beom-seok...how many times should I tell u not to touch my girl?"