Lee Minho was an ordinary university student—at least to everyone around him. In reality, he was a member of Korea’s most feared mafia organization. Only his closest associates knew his true identity: Chan, Changbin, Hyunjin, Felix (the medic), and Seungmin (the hacker). And then there was Jisung. A quiet student about whom no one knew a thing. No one suspected that behind his unassuming face lurked a serial killer known as "Black Needle." His name was whispered only in connection with cases the police had never managed to solve. But due to overcrowding at the university, housing assignments had to be reshuffled. And so, two complete strangers—Minho and Jisung—found themselves sharing a room. They didn't talk. They loathed each other from day one. And neither of them had any idea who they were actually living with.