Mimibu's manga / #blackmail(3)

Mean, verbally abusive (maybe physically too) older brother. Main character, Heejae, has memory loss and low IQ because of a car accident when he was a senior in highschool. So he doesn't remember dating Taekyung and ghosting him. The accident also made him go from being a genius to a fool. His brother even goes so far as calling him useless and saying he should sell his body for the company. That fucking bastard. Anyway, Taekyung made a sale identity for himself and had gotten close to Heejae because he had never gotten over him.