Kwang Su (Shin Hyun Jun) has struggled his whole life to shake off the stigma of a shameful family history. He lives in a state of perpetual despair. By contrast, Jong Man (Lee Byung Hun) works as a bartender and spends his days dreaming of becoming an international movie star and his nights filming himself and contacting top Hollywood production companies in the hope that one day he will get his lucky break. Then there is the shy girl Se Hee who works in a music store. When Kwang Su stumbles into the music store, blind drunk, but still able to bash out a tune on a piano, Se Hee falls instantly in love. When Kwang Su stumbles into the bar where Jong Man works, he finds himself arrested for his brother's murder. But fortunately he manages to escape from the police, bumps into Jong Man who instantly lets him stay in his apartment.

Following the final events of General's Son 2, Kim Du-han is forced to go on the lam but eventually returns to Jongro where he attempts to rebuild his gang with the brothers that are still alive and loyal and defeat Hayashi's Yakuzas once and for all.

One day, Hyun-joon, a policeman who lives with his mother and his daughter, attains a superpower after getting struck by the lightning. After the incident, Hyun-joon realizes that there are others who have been going through the same situation with him, and gets involved with unexpected situations. Will he be able to succeed both, as a father who struggles with the relationship with his daughter, and as a cop with a superpower who is eager to catch an evil criminal?