The Weakest Contestant of All Space and Time Vol. 1 (manga)
HHitomu is a young salaryman with a monotonous life until he is transported to another world. Now he’s forced to fight to the death in an interdimensional gladiator tournament!
After losing repeatedly, Hitomu is set against four weakling opponents. But instead of fighting them, he escapes, breaking out his fellow “losers” with him: a ghost boy, a slime girl, a useless robot, and a bug monster. Now fugitives on a hostile planet, the motley crew must rely on each other to survive!