Apparently, Disillusioned Adventurers Will Save the World, Vol. 1 — Shinta Fuji

Nick is a knowledgeable and skilled adventurer who always gave his party his best -- that is, until he got framed and unceremoniously kicked out! He hits rock bottom when his girlfriend dumps him, but before long, he finds kindred spirits in a former noble lady, an excommunicated priest, and a dragonian warrior he meets at a bar. Having also lost faith in humanity after individual betrayals, these three share Nick's distrust in others. That isn't all they have in common, though -- all four are in dire need of money. Thus begins the story of the world's greatest adventuring party!