As far as confusing Anime go, This one sure starts you off in the middle of some mayhem you really need to keep watching to get your head around it.
It's theme is around the Mafia sometime around 1930's - 1940's, But the thing with this anime is that it would be focusing on something happening in 1938 with one character then drop back to a different character in 1936 and do this all the way threw with several main characters until their story's all start coming together and you see everything unravel and make sense.
With immortal mafia member's, A potentially unseen God, A nearly immortal terrifying assassin, A comedy duo, A sadistic mafia member and a kid who cry's before he get's into fights this anime is very well made and is well worth a watch if you want something to think about and enjoy.