Seven years after the events of Gundam Build Fighters, the rules of Gunpla have been renewed, and the sport becomes even more popular. However, one academy is left behind in this change, and that was Seiho Academy, which Sei Iori once attended. The only member of the Gunpla Battle club remaining is Fumina Hoshino, who befriends Sekai Kamiki, a boy who has been training with his master in martial arts and the young Gunpla builder Yuuma Kousaka, and together, they attempt to secure a place in the world championship as the "Try Fighters" (トライ・ファイターズ Torai Faitāzu?).
Shortly after the Arista that produces Plavsky particles is destroyed in the final episode of the previous season, Plavsky Particle System Engineering (PPSE) is acquired by Yajima Industries while American scientist and Gunpla fighter Nils Nielsen and his girlfriend Caroline Yajima rediscover Plavsky particles aboard the International Space Station. With new Plavsky particles produced, the sport of Gunpla Battle continues worldwide.
In Gundam Build Fighters Try, the one-on-one battle format is replaced by battles between teams of three Gunpla fighters and is divided into two categories: one for players under 19 years old and one for older players. In addition, damage levels can now be set on participating Gunpla.
New rules have been added to Gunpla battle:
- Non-mobile suit support units such as Core Boosters count as one Gunpla unit.
- Mobile suits that combine such as the Double Zeta Gundam or Victory Gundam count as one unit, but must be controlled by only one person when separated into multiple units.
- Teams may use only one mobile armor in battle, with all three members piloting it.
- Teams can change Gunpla before each match; changing Gunpla during a match is forbidden.
- Each match has a 15-minute time limit.
- If both teams have the same number of Gunpla left after the time limit expires, the match is declared a draw; each team will select a representative for a one-on-one battle to determine a winner.
- BG-011B Build Burning Gundam
- TBG-011B Try Burning Gundam
- LGZ-91 Lightning Gundam
- LGZ-91Fb Lightning Gundam Full Burnern
- SD-237 Winning Gundam
- SD-237S Star Winning Gundam
- RGM-237C Powered GM Cardigan
Seiho Academy's Plamo Club (プラモデル部, Puramoderu-bu)
- LM312V04 Amethyst Victory Gundam (Custom Victory Gundam)
- G-P.A.R.T.S DELTA G-Bomber (Custom G-Fighter)
- ZZ-999 Zeo Zeong (SD Custom NZ-999 Neo Zeong)
- Super Xamel (An upsized YMS-16M
Celestial Sphere (ソレスタル・スフィア, Soresutaru Sufia)
Great K (グレート・K, Gurēto Kei)
Tiger & Rabbit
Build Busters (ビルドバスターズ, Birudo Basutāzu)
- GN-003α Salty Kyrios (Custom GN-003 Gundam Kyrios)
- RX-110β Screw Gabthley (Custom RX-110 Gabthley)
- GAT-X370γ Raider Lagoon (Custom GAT-X370 Raider Gundam)
- S×D×G Gundam
- SDG-R1 Snibal Gundam
- SDG-R2 Dragonagel Gundam
- SDG-R3 Giracanon Gundam
Titan (タイタン, Taitan)
- NK-13J Denial Gundam
- LM111E03+SD-VB03A Gundash Blastor (Custom LM111E03 Gunblaster with LM312V04+SD-VB03A V-Dash Gundam's Overhang Pack)
- GNY-003CL Gundam Abulhool Plus (Custom GNY-003 Gundam Abulhool)
Von Braun (フォンブラウン, Fon Buraun)
- PF-78-3A Gundam Amazing Red Warrior
- GW-9800 Gundam Airmaster
- OZ-15AGX Hydra Gundam (with parts from the Endless Waltz versions of XXXG-01D2 Gundam Deathscythe Hell and XXXG-01S2 Altron Gundam)
- KUMA-F Beargguy F
- Kouki Gundam
- Musha Godmaru
- GSX-401FW Stargazer Gundam
- RGM-111 Hardygun
- OZX-GU01A Gundam Geminass 01
- MS-06V Zaku Tank (RX-75-4 Guntank colors, with RGM-79 GM head)
- MSJ-06II-C/B Tieren High Mobility Type B
- ZMT-S16G Memedorza (Pink Colors)
- GPB-06F Super Custom Zaku F2000 (MSJ-06II-A Tieren Ground Type Colors)
- WD-M01 ∀ Gundam (TAKU Custom)
- MS-05B Zaku I
- RX-78NT-1 Gundam "Alex"
- XXXG-01S Shenlong Gundam (Pink Colors}
- TGM-79 GM Trainer
- RX-0 Unicorn Gundam (SD Version)
- Devil Dragon Blade Zero Gundam
- RGM-89 Jegan
- RMS-188MD Zaku Diver
- MS-14D Desert Gelgoog
- MS-06D Desert Zaku
- GT-9600 Gundam Leopard
- RGM-86R GM III
- MSJ-04 Fanton
- MS-08TX(EXAM) Efreet Custom
- GN-009 Seraphim Gundam
- OZ-13MSX1 Vayeate
- OZ-13MSX2 Mercurius
- MSM-03C Hygogg
- MS-14J ReGelgu
- RGM-79Q GM Quel
- MRX-010 Psyco Gundam Mk-II (in the colors of King J-der from The King of Braves GaoGaiGar)
- AMX-014 Döven Wolf (ORX-013 Gundam Mk-V colors)
- ZGMF-X09A Justice Gundam (in ZGMF-X10A Freedom Gundam colors)