Tsurugi Tatsuno is a boy who competes in Virtual Digimon Battle tournaments. When a Kuwagamon appeared in the Real World, his Greymon came to life and protected him. Piximon summons Tsurugi to the Digital World to save it from the evil Barbamon. Because his Digimon bears a hexagon shape, it is an Illegal Digimon, meaning that Digimon with this symbol can help save the Digital World. Tsurugi's Greymon later De-Digivolves to Agumon, and they meet other characters destined to save the Digital World from Barbamon's forces. Now they must stop Barbamon and his minions before they collect all the DigiMemories and take over both worlds.