Blues Joe

(from ebookjapan):
This is a gory yakuza action tale about the activities of Joji Oyamada, aka "Blues Joe," a two-faced gangster who helps out at a rice shop by day and is an assistant to the Mitarai clan's young boss by night, a man of honor and integrity. Jiro, a yakuza from the Mitarai clan, promises to marry Katsuko, a hostess who claims to be a lifelong loner. However, Jiro learns that Katsuko has a family who sends money back to her, and that she has received a large sum of money from Kurumizawa, a yakuza who is more than a yakuza.......?

Note: The original tankobon release was 3 oversized volumes, but the digital edition has the content split into 6.