His sister went through a horrible experience when she was only 15, she could've been almost raped or worse- actually raped. as you've seen, the assault was so bad that she was hospitalized. please understand that this is not the 'sister complex' that is the same as those u see in most highschool shoujo mangas, it isnt even similar. if this happened to my younger sibling, i wouldve carried the guilt for the rest of my life. i cannot imagine having the chance to protect my younger sister but letting it go and in the end, something happens to her. ik im being long winded blahblahblah but i hope i got the message across :(
His sister complex is annoying af.
I don't care that it is because of trauma, at least female lead is dealing with her problems like a champ on the other hand.