Ningen Fushin no Boukensha-tachi ga Sekai wo Sukuu you desu

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!

(Source: Yen Press)