Graveyard of Honor (1975)
Graveyard of Honor (仁義の墓場 Jingi no hakaba) is a 1975 yakuza film directed by Kinji Fukasaku. It is based on the life of real-life yakuza member Rikio Ishikawa, who is played by Tetsuya Watari. Noboru Ando, who plays Ryunosuke Nozu, was actually a yakuza member before becoming an actor.
More at Wikipedia.