Hwansaeng Boss 

'Break my organization with my own hands.' Gang-Jin Faction boss Lee Gang-Jin is the last skilled gangster in the dark world. He unified the country with his fists and rose to the top, but was betrayed by his favorite dongsaeng Jo Du-Yeong and died. At the moment of his death, he wakes up in the body of Lee Gang-Jin, a high schooler who took his own life due to school violent. Meanwhile, the Gang-Jin Faction starts a 'Kkanglin Audition' under the pretext of recruiting young members, and delinquent teenages are eager to join. After repeated regrets, Gang-Jin decides to take control of the Gang-Jin Faction he founded with his own hands to reverse everything...