Yakuza Zombie

Overview
Yakuza Zombie opens with an introduction to a mysterious Yakuza graveyard deep in the forest, and a story of the baddest Yakuza of them all, Naruo Ryuuji (shown in cut scenes played by Ozawa Hitoshi). Naruo Ryuuji was a fearless killer who eventually got into heroin and, exactly like Ishimatsu Rikuo in Takashi Miike's Graveyard of Honor, eventually leaps to his death from the top of a prison, claiming he'll be back. I'm assuming this is a reference to real life crazy Yakuza Ishikawa Rikio, whom the original Graveyard of Honor was based on. It's established that the corpse of the fierce Yakuza Ryuuji is buried in the graveyard beneath a marker with the Japanese characters "Jingi" (Honor), and then we are taken to the modern day.
Similar
Brother (2000)
Kill Bill: Vol. 1 (2003)
The Flower and the Sword (1964)
The Outer Way (1998)
Unification of Japan 27 (2018)
The Great Okinawa Yakuza War (1976)
The Viper Brothers and the Young General (1975)
The Viper Brothers: Prison Gang 13 (1972)
Crying Freeman (1995)
Contract Killer (1998)
Detective Bureau 2-3: A Man Weak to Money and Women (1963)
House of Gamblers (1970)
Dead or Alive (1999)
Ichi the Killer (2001)
Adrift in Tokyo (2007)
Wharf Temperament (1961)
Pinocchio: A Man Without Nationality (1997)
The Hungry Shinjuku Detective (1994)
True Record of an Ando Gang Side-Story: Starving Wolf's Rules (2002)
Big Shots Die at Dawn (1961)