The "Second GunPla Boom" has become a global sensation, sparking widespread interest in GunPla Battles. In this competition, competitors use Gundam plastic models to battle it out. Sei Iori, a first-year middle-school student and the lone son of a model shop owner, possesses impeccable skills in constructing GunPla but lacks the know-how to excel in the Battles. He finds a like-minded individual in Reiji, an accomplished Gundam Fighter whose origins remain unknown. United in their quest for victory, Sei and Reiji aim to emerge victorious in the world championships of GunPla Battles.