Novice goddess Ristarte is assigned to save Gaeabrande, a world rated S-rank for difficulty, from its Demon Lord. She summons Seiya Ryuuguuin, a Japanese human whose stats far exceed every other candidate, only to find that he refuses to set foot in Gaeabrande until he has trained to absurd overkill levels. He buys three sets of armor (one to wear, a spare, and a spare for the spare), opens with maximum-power attacks on the weakest slimes, and incinerates corpses to confirm they are dead. Ristarte narrates the whole ordeal with mounting exasperation.