Men of the underworld (2015)

1st in a 6-film series. The W.R.C. is the largest yakuza-run conglomerate in Japan, and a war for succession begins when the current Chairman suffers a fatal traffic "accident". Tadano (Namioka Kazuki), the secretary to the current Vice-Chair Konno (Noguchi Masahiro), is the only survivor and is haunted by flashbacks. His brother-in-arms, Board Director Umehara (Ozawa Hitoshi), a fellow Zainichi Korean, is in competition with the ruthless Director Tamura (Sugata Shun) for the top spot. The feud is goaded by the secret placement of spies within the WRC by the Tokyo Police's "Unit Zero", spearheaded by the sly Inspector Sano (Shinsui Sanshou), and cracks begin to form in the organization and between brothers ...