While I want this to be a love story, it isn't.
Bum is stalking a former classmate and comrade that was kind to him a few times. He has been testing the lock on his house for several months and finally manages to get the code correct. However, once he gets inside the house he finds a woman chained up in the basement, and quickly finds himself meeting a very different Sangwoo than he expected.
I want to cry.
Killing Stalking