I think most people is getting this wrong....this is NOT LOVE, don't get the wrong idea. Sangwoo looks for Bum desperate because he does not want him to escape. Just think about how problematic would it be if Bum had escaped and gone to the police...Sangwoo wants to DOMINATE him as he only feels at ease when he is able to control other's people lives. Due to some trauma from his childhood he has developed a personality that lacks empathy towards others, he is a sadist. So this is NOT a LOVE story, but a very good psychological manhua.
Killing Stalking