What do you want to know?
Everything
Everything up to the end (the important stuff)
The thing is the manhwa is not finished as far as I know. The raws just kind of never got updated again. But basically what happens up until the hiatus is we get a flashback that delves a bit into Bit chan's childhood to show how he's always been obsessive when he likes someone and the extreme measures he can take in order to keep that person around. If I remember correctly there was this girl older than him that I think was his babysitter or something that he was really close with. When she decided to leave to go to uni (I could be misremembering) he poisons her food so that she can't leave. After this event the parents take him to a psychologist and they explain to them Bit chan's problems but nothing really changes. Then the flashback moves forward in time, to the current university days. After hanging out with his friends, with the MC's sister ranting about how much of a piece of shit her brother is and that Bit chan should avoid him at all cost, he arrives at uni, gets out of his car and sees the MC for the first time and with one look at his face he is instantaneously smitten. The rest of the flashback focuses on his downward spiral of obsession and ends with him preparing the annex in his apartment where he is going to keep him hostage. Back in the present, Bit chan returns home. The MC has already simmered down, unable to leave, and they take a bath, have sex and that's where things leave off. If someone has more infornation than me or knows if he story continied beyond this point, I'd really like to know.
Can someone fckng spoil me