Following a grueling struggle, the ultimate stage of the Gunpla Battle U.S. Championship has arrived, but a surprise contender happens to enter the fray. In the aftermath of the competition, Misa Satsukino is building a new Gunpla in Ayato Shopping Street while feeling despondent. In an effort to alleviate her downheartedness, she tries running a simulation with her creation, only to encounter an unexpected setback. The destiny of the Gunpla Fighters hangs in the balance at the upcoming GB Festa occasion, where the stakes are more elevated than ever before.