Xin and the Hi Shin Unit ride into Qin's Sanyou campaign as reinforcements for General Kanki's army, which is pushing into Zhao territory for a decisive battle. Xin keeps chasing his goal of becoming the greatest general under the sky while serving young king Ying Zheng's drive to unify a fractured China, and fighting on someone else's campaign puts his unit through its toughest test yet. It picks up directly from Kingdom's fourth season, continuing the same Warring States war rather than offering newcomers a jumping-on point.