I think that the one who put those guys to rape Si-woon was his brother (i can't remember his name lol). In chapter 4, page 19 he said that "i don't care if you cry for my help and make a scene in front of me like last time". I think that "the last time" was when Si-woon was raped and his brother was watching him (or he was the one who recorded idk Σ(  ̄□ ̄||)). Maybe that could be the reason why he doesn't wants Si-woon to go at school, because he could find out. (●'◡'●)ノ
I think that the one who put those guys to rape Si-woon was his brother (i can't remember his name lol). In chapter 4, page 19 he said that "i don't care if you cry for my help and make a scene in front of me like last time". I think that "the last time" was when Si-woon was raped and his brother was watching him (or he was the one who recorded idk Σ(  ̄□ ̄||)). Maybe that could be the reason why he doesn't wants Si-woon to go at school, because he could find out. (●'◡'●)ノ