Gundam Build Fighters: GM no Gyakushuu
Japanese title: ガンダムビルドファイターズ GMの逆襲
Alternative titles: Gundam Build Fighters: GM's Counterattack
Type: ONA
Source: Original
Episodes: 1
Status: Finished Airing
Aired: Aug 25, 2017
Duration: 31 min
Rating: PG-13 - Teens 13 or older
Studios: Sunrise
Producers: Sotsu, Nozomi Entertainment
Genres: Action, Sci-Fi
Themes: Mecha

The day before the ceremony marking the completion of the Yajima Stadium, Nils Nielsen invites Sei Iori, Meijin Kawaguchi, and others to an exhibition battle using the new large-scale battle system he has designed. Now that they are all reunited, Sei attempts to show off the Build Strike Cosmos that he has upgraded for the exhibition, but then he notices something missing... Meanwhile, somebody takes control of the stadium's systems, sealing Sei and the others inside. Before them appears a mysterious group, which has come to challenge them to Gunpla Battle.

(Source: Sunrise)