Jisung was a psychopath and a sadist, and a serial killer. He was deemed insane by the court and was sent here. Many doctors couldn’t handle him because he’s talk nonsense to them and himself. Whenever he doesn’t like someone, he either doesn’t interact with them or becomes violent with them. When he does like someone, he becomes really possessive and clingy and hates when that person talks to someone else. In this case, hyunjin. Hyunjin is taller than Jisung at 5’10.5, compared to Jisung’s 5’7