Because it's Sungho (not Dohyun) who says "please kill me". All he wanted was to confess and get his feelings returned. But he understands now that Dohyun will never feel the same and that he's the only one still living in the past. So now the only option is death (in order to be free from his emotional shackles). Honestly, I really don't like Dohyun. From the beginning I didn't really empathize with him. And now that we know the past, I get why.
because the translations are wrong in that part,Sengho tells Dohyun after the later says he is going crazy "what was it that you said? its over? no its not" something to the context,which makes Dohyun freak out and look around the room ( looking for a new way out after he realized that it isnt just simple revenge and Sengho actually is obsessed with him and wants to keep him forevaaa) so he freaks out,looks around the room,realizes he has tried everything,it hits him that there is no way out and he gets depressed and begs Sengho to kill him,saying that he tired of this and doesnt know what to do anymore and that death is better than this.
I didn't quite get the reaction of Dohyun after Sungho finally confessed to him. He nearly lost it all of a sudden...why? He seemed to look around in the room and said "Yes, it's true please.....kill me" Did he finally remember the past? Because he said "You're tired of the past, just like me. I don't know what to do. Just. I'll feel better when I just die. It hurts too much." All of a sudden...? Before he couldn't get enough of reminisce about the past. So....did he remember? Or was it just that he couldn't handle this whole situation anymore after nearly getting killed? On top of that he got a confession in this fucked up mess... . In the end is it just too much for him or is there another reason? What do you guys think?
Dohyun don't give up now!! You came this far! You can make it!!! Go on my child!!! (/TДT)/