After being arrested for scaring a gang at a back alley with his martial arts skills, Sekai Kamiki arrives at Seiho Academy as a second-year transfer student. As the last remaining member of the Gunpla Battle Club struggling to form a team to participate in the upcoming Gunpla Battle Tournament, Fumina Hoshino convinces Sekai to join her club.

Sekai is transferred to the same class as Yuuma. Meanwhile, Sekai and Fumina must battle Miyaga, Yuuma, and Eri Hoshino in a two-on-three battle to save the Gunpla Battle Club from being absorbed into the Plamo Club.

The Try Fighters have their first practice game with a female trio from Saint Odessa Girls' School.

Word spreads quickly of the Try Fighters' victory over the Song Dynasty Vase team, which has other teams on edge. Meanwhile, as the Try Fighters practice for the West Division qualifiers, Fumina takes Sekai on a date to G-Muse, a Gundam museum and shopping center. There, they encounter an arrogant Gunpla builder from Osaka.

Following his humiliating defeat at the hands of Minato Sakai, Sekai struggles to adapt his Jigen Haoh School techniques in different environments while Yuuma upgrades his Lightning Gundam. Meanwhile, Fumina reveals her inspiration for taking up Gunpla Battle as a hobby, and she completes her latest Gunpla just in time for the qualifying tournament.

Shortly after winning their first battle, the Try Fighters face Team SRSC, which is favored to win the championship. Certain that they cannot win in their current condition, Fumina decides to reveal the secret power of the Winning Gundam.

The Try Fighters make it to the quarterfinals, but have to face a rookie team that relies on straight-builds - Gunpla kits that are built straight out of the box without any touch-ups. The team's leader is Shimon Izuna, a former boxing champion who proves that a fighter's raw skill can outperform any opponent with a snap-fit Gunpla, and Sekai and his partners' resolve is tested when Shimon's teammates beg them to concede their match for the sake of his younger brother.

The time comes for the semifinals and Song Dynasty Vase takes on G-Master. Gyanko is determined to face against Sekai in the others in the finals, until the West Tokyo champions show their true power.

The Try Fighters face G-Master for a spot at the national tournament. For Sekai, this is his chance to avenge Gyanko's defeat.

The Try Fighters have won the West Tokyo Division finals and are taking a much-deserved break before the national tournament. Meanwhile, Mirai is selected to represent her talent agency in a Gunpla battle between fashion models. To prepare for this event, Yuuma helps her with her first Gunpla.

To prepare for the national tournament, Mr. Ral brings the Try Fighters to a special training camp. But just as they prepare for a trial battle, someone from Yuuma's past returns to haunt him.

Following the Try Fighters' humiliating defeat at the hands of Saga Adou and the intervention of Meijin Kawaguchi III, Sekai loses consciousness due to continuous assimilation with his Gunpla while Yuuma runs away. The Meijin challenges Yuuma to a Gunpla battle to reveal why Yuuma lost the fight, and Fumina encounters the person who inspired her to take up Gunpla battle.

After Sekai wakes up and proceeds to Nielsen Labs' workshop to repair his Build Burning Gundam, he encounters a mysterious girl who admires his Gunpla. He later on participates in a battle royal between members of other teams at the facility.

Taking what they have learned from their stay at Nielsen Labs, the Try Fighters upgrade their Gunpla for the upcoming national tournament. Meanwhile, Minato enters the championship scene by joining a high school team and winning the Osaka qualifying finals.

The national tournament begins, and the Try Fighters put their upgraded Gunpla to the test.

As the first round of the national tournament continues, Minato and Shia unleash their Gunpla.

The Try Fighters battle Team SD-R in the second round of the tournament. However, their battle takes place in a haunted castle, which gives Yuuma the creeps.

With Team SD-R revealing the true form of their Gunpla, the Try Fighters must figure out how to defeat their opponents to advance to the next round.

Yuuma receives the Try Burning Gundam's spare parts from China, but is cornered by a pack of muggers on his way back to his team's hotel. Meanwhile, the Try Fighters are set to face Tenzan Academy's team, which has a member that uses the same martial art as Sekai.

The battle between Sekai and Junya rages on, as both combatants unleash the full potential of their Gunpla.

In the semifinals, Celestial Sphere face Von Braun. However, something is amiss when Wilfrid notices Lucas Nemesis fighting alone.

The Try Fighters face the Build Busters, with Yuuma and Minato finally settling their score.

As the Try Fighters and Celestial Sphere have two days to prepare for the final round, Yuuma locks himself in his hotel room with all three of his team's Gunpla to come up with a solution to counter his opponents' strategy.

The final round has begun, and only one team will walk out of it with trophy in hand.

Following the aftermath of the national championships, Yuuma and Minato continue their rivalry in the Gunpla Builder's Contest Meijin Cup. Upon a heated argument on the outcome of the contest, both men settle their differences in a Gunpla Battle, which suddenly becomes a free-for-all with everyone in attendance involved.