Apparently, Disillusioned Adventurers Will Save the World, Vol. 5 (manga) — Masaki Kawakami

A party of adventurers, beaten down by a cruel world, tied together not by trust or love but by necessity… A description of Nick and the Survivors that could fit just as well for Leon, Claudine, and the Iron Tiger Troop! So when Nick steps into the ring and raises his fists, he's grappling with a giant tiger-man…and with the vagaries of character and fate. What led his foe astray? And would one wrong step have sent him down the same path…?