But, guys, you miss something, more you know someone, more the suffer will be deep. Taeyang ruined his school life during months or more, years, here Lila ruined nothing, she just fucked up, when you know someone since a week you don't really care/suffer, but she helped (maybe involuntarily) him to wake up and move his ass, and we all know that her past is fully or in part true, she is tortured by this. Some guys would just ingore, some, not, Joonwoo chose to help her. Plus, it's not a pig like his past "friend" the piggy fucker one, who would ruin again his life lol