Gangsta, Volume 1 collects the first five issues of Kohske’s eponymous SF crime manga. First published in 2011, the English language edition came out in 2014.
Ergastulum is a hive of scum and villainy, populated by monsters and victims. The cops are crooked, the criminals are in charge, and life is for the most part unpleasant.
Worick Arcangelo and Nicolas Brown are handymen. They handle problems the other people of Ergastulum are unwilling or unable to face.