A Gundam show that knows exactly what it is: thirty minutes of watching custom mecha kill each other in a simulator, no existential weight required. The animation treats every GUNPLA battle like it matters, cutting between beam clashes and melee combos with the energy of a tournament arc that's never heard of filler. It's shameless advertisement dressed as entertainment, which works because the entertainment part is real.

The GUNPLA Battle U.S. Championship reaches its final round after hard-fought matches, and a certain fighter makes an appearance there. Some months later, Misa Satsukino is working on a new GUNPLA in the Ayato Shopping Street and is in an even worse mood than usual. To vent her restless anger, she puts the finished model into a simulator and heads into battle, only for her GUNPLA to be abruptly held in place. With the big GB Festa event about to begin, the GUNPLA Fighters face a turning point. The six-episode ONA is a mecha story built around model battles.