Ginta Toramizu, a nearsighted Tokyo middle-schooler who has dreamed of the same fairy-tale world 102 times, is summoned into MÄR-Heaven, where his weak body turns strong and his eyes need no glasses. There he meets the witch Dorothy and comes into possession of Babbo, a talking ÄRM and one of the magical weapons that decide every fight in this world. Learning to wield ÄRMs pulls Ginta into the war brewing against the Chess Pieces, even as he keeps looking for a way home.