As the GUNPLA Battle U.S. Championship reaches its climax, a mysterious fighter emerges, sparking a new chapter at the intersection of two worlds. Months later, Misa Satsukino, amidst her construction of a new GUNPLA in Ayato Shopping Street, finds herself unusually agitated. Channeling her pent-up frustration, she launches her creation into a simulator for combat, only to face unexpected obstacles. With the looming GB Festa on the horizon, the destinies of the GUNPLA Fighters hang precariously in the balance.