Jin, jimin, tae and hoseok, all of them are big bullies in school. All of them bullied jungkook terribly, who was new to school. That's how jungkook's life goes, one day jin asked him jokingly "Your mother has many boyfriends, so I ask, is your father really Mr. Jeon namjoon?". So jungkook cries and asks his dad about it, because of that he is greatly affected in his life. 15 years later, jungkook's calm demeanor turns psycho and returns to take revenge on everyone who made him this way.