In December 2006, Kazuma Kiryu and Haruka Sawamura are living a peaceful life, but Tojo Clan chairman Yukio Terada appears and asks for his help in preventing a war between the Tojo and the Osaka-based Omi Alliance. The group is ambushed by Omi assassins and Terada is fatally shot, asking Kiryu to negotiate peace in his place. Kiryu recruits former comrade Daigo Dojima to become the new chairman, and the two travel to Osaka, where Kiryu forms a rivalry with the Omi chairman Jin Goda's son, Ryuji Goda. Ryuji refuses the idea of a truce between the Omi and the Tojo and attempts to stage a coup, but they are interrupted and arrested by the Osaka police, led by Detective Kaoru Sayama. Sayama makes a deal with Kiryu to help him stop the Omi threat in exchange for information on the Tojo, as she believes they are connected to her parents' disappearance as a child.