Psychopath Jeon Jungkook has tortured by his father to be perfect for 13 years . Due,to his father death it affected him so much that he become an psychopath at age 13 . Killing gives him peace . But,he killed bad people only . When,Jungkook becomes adult (22) he becomes friends with a psychologist student of Busan University Yeh Shuhua he plans to kill her because he never killed a girl so,he wants to know how it feels . But,in a sudden he falls for her!