Finn Lane, a teenager via Isekai Transfer, awakens a card Summoning System in a world where cards fend off enemies. He starts with useless low-rank Common Cards and is looked down upon. He takes an unconventional approach, breaking through with sheer quantity, clever strategies, infinite copying abilities, and making a name in competitions. Fighting an evil secret organization and the Monster Horde, the young man rises against the odds and shakes the era.