Where to Watch Proud Ambition 4 (2006)

After the retirement of boss Tokumaru, Sunagawa succeeds him as the sixth head of the Morita family, and Kano Kenji seizes the opportunity to plot the succession of the Matsuura family. Kano, who had been serving a prison sentence, is granted parole after helping a prison guard. With everyone's intentions intertwined, the day of his parole is approaching sooner than expected.