Apparently, Disillusioned Adventurers Will Save the World, Vol. 1 (manga)

"Veteran adventurer Nick s life is falling apart. Despite all the knowledge and expertise he s devoted to his adventuring party, his respected leader kicked him out, his girlfriend dumped him, and his teammates shamelessly accused him of embezzlement. Tired, heartbroken, and looking for a drink, Nick chances upon a few kindred spirits who are jaded as he is. Together, these disillusioned adventurers form an unstoppable team out to save their bleak, depressing world! "--