In Seoul, you need to be tough and smart in order to survive. Mafias are everywhere. Left and right. In front of you or behind. Your older brother, N, also known as Hakyeon, decided that you can finally become a part of his mafia. The mafia includes of him, Leo, Ken, Ravi, Hongbin

Being a trainee is difficult. But with a new program where sunbaes help the trainees is even more difficult. Why?