Haruhiro wakes in the fantasy world of Grimgar remembering nothing but his own name, surrounded by strangers in the same state. With no way home, the group is pressed into service as trainee volunteer soldiers under Red Moon, the Alterna Frontier Army's reserve force, paid for the monsters they put down. Haruhiro ends up in a party with the level-headed priest Manato, the loudmouth Ranta and a few others, all of them barely trained and stumbling through their first clumsy skirmishes against goblins.