''Friend: The Great Legacy'' begins 17 years after where the previous film left off. Lee Joon-seok, who claimed responsibility for ordering his friend Dong-soo's murder (despite having nothing to do with it), has spent a lot of time behind bars and now he is released to a world that is as unfamiliar to him as the criminal organization he used to lead. With his subordinate Eun-ki now practically parading as the boss, Joon-seok, a leader by nature, secretly embarks on a mission to subvert his current position. He invites Choi Sung-hoon, whom he'd met in prison, and Sung-hoon's gang to join in his plan. Sung-hoon is the twenty-something son of one of Joon-seok's female friends in high school who now works as a bar hostess, and he had been serving a one-year sentence for beating his mother's abusive husband. Having developed a respect for the charismatic Joon-seok in prison, Sung-hoon willingly takes his side. But when he discovers the truth behind his background, this creates great tension between the two. Interspersed are scenes of Joon-seok's own father, Lee Chul-joo as a kkangpae who founded the criminal organization in 1963 Busan.