The Towada Family of the Yamaji-gumi—whose main headquarters is in Osaka—has risen to become the largest organization in Yokohama. At its core stands Tenkichi Mitsuyoshi, supported by the formidable Morisuka Brothers. The elder brother Kazuma (Show Aikawa) and the younger Misao (Kazuki Namioka) strengthened the combat-oriented Tenkichi-gumi, using their overwhelming force to seize control of Yokohama. But their dominance brings resentment within the ranks. When the second-generation boss collapses, the family fractures. A breakaway faction forms the Kinshishi-kai, expanding rapidly—and soon the brothers, the very "nucleus" of the Tenkichi-gumi, become their primary targets.