After just finishing the entire series (5 films in all) I must say that this series is DEFINITELY worth a watch, especially for fans of dramas centered around crime families with a healthy dose of violence to help spice things up.
It follows mainly Shozo Hirono, and his journey from an ambitious and stoic slum-dweller in the bombed out crater of the Hiroshima bomb site. As him and his war buddies climb the ranks of the Yakuza, greed, honor and betrayal force the families into various conflicts in a never ending cycle of power struggles.
Stylistically this film, and all the others, are excellent, with a consistent jazzy theme accentuating the more important points and giving each entry a familiar feel to the last one, yet not one which ends up feeling boring or overused. The camera work is fantastic and the scene composition is where I am most reminded of the Italian-American titan of cinema that this review invokes. Many of the scenes are around crowded tables at family meetings or in shadowy bars with table lamps and cigarette smoke twirling in the air.
All in all I love this series and if you have a chance, absolutely watch all five. If anything give this first entry a chance and you will not be disappointed.