This humorous, quirky and at times emotional look into the world of Japanese criminals is probably the best manga you have never read.
The plot is simple and unfortunately, by volume 40 (which is where I'm up to), I feel it is getting rather repetitive. Shizuya is a quiet, docile and just downright horrible lingerie designer by day. By night, he is trying to keep himself from being toppled by his subordinates, deal with local troubles or repel the determined Yakuza from Osaka. Occasionally, a woman will fall in love with him...
The outstanding cast however, more than make up for the simple story. While many side-characters (and there are many) only appear as comic relief, the central ones, especially Shizuya, are very human.
Given its length, it would make very dull reading if the story sprayed 20 litres of blood on your face with the turn of every page. Luckily, this is a very lighthearted and absolutely hilarious take on Yakuza life.
The art, which can look like newspaper comic strips during comedic events, can take a 180 degree turn for serious scenes to fully capture the glamour, violence and distress that is being a Yakuza. It's not the best, but it fits the story very well.
All in all, if you got 30 minutes to do some casual reading, pick up a volume of Yakuza Side Story. You will not be disappointed.