Distraught over having his fortune taken from him, Taiya heads out to find his mentor who is behind all this.

Ishirou has been out of contact with Taiya for days when he suspiciously reappears, while at the same time, a space pirate appears with something important to give to the Boonboomger.

Taiya is devastated with Bundorio's apparent death and attempts to fix him up. Meanwhile, Dissrace returns and initiates a plan to turn the public opinion against the Boonboomgers but Sakito and Byun rise against him.

The Boonboomgers came to the after-school daycare facility where Taiya used to attend. There, they learn about Taiya's first love. While they are having a good time talking about their sweet and sour memories, a new Grumer appears, and Taiya and Sakito are put to sleep by a mysterious attack...!?

Genba has a heart-to-heart with someone he least expects. The Boonboomger use a new invention to transform into a powered-up form to confront Mad Rex.

Mira is propositioned into a political marriage with Spindor as the team struggles with the fact that they may have lost.

The Boonboomger enter the final lap of their battle with the Hashiriyan.

Taiya is seriously wounded after his fight with Mad Rex and Shirabe informs the team that the ISA decided to have the Boonboomgers disbanded and their equipment confiscated.

After Genba having successfully activated BoonBoom Safari, Ishiro and Mira pay a visit to an aquarium looking for inspirations to activate BoonBoom Marine, when the Sanseater return with a fixed-up Boonboom Killer Robo, eager for a rematch.

Jou finds a monster created by the Hashiryan who refuses to attack humans and befriends him, determined to protect his new friend from the enemy.

The Boonboomgers meet Sakito Homura, a mysterious man who possesses the same powers as them, able to transform into Bun Violet and whose intentions are unknown.

At the Hashiriyan's request, Sakito starts trying to get rid of the Boonboomgers! Taiya asks him, "Why did you abandon the earth?" But...!? Will Sakito turn out to be a friend or foe!?

Cannonborg is on his last legs, initiating a plan to destroy Earth from space.

A new powerful enemy has arrived, and Genba seems to have some history with him...

Sakito and Byun help with Ichiro's spy job, while Taiya tells the others the story of how he and Ichiro met.

Taiya and the others are astonished upon discovering that Bundorio was once a Hashiriyan and worked with Wild Spindor.

Ichirou bumps into a spy with whom he used to work with, while the others are called into action to deal with a camera monster.

Jou wants to become a Boonboomger, but Taiya rejects him, saying he doesn't have what it takes just yet.

Taiya reveals his real intentions to form the Boonboomgers, which is to participate in the "Big Bang Grand Prix", the biggest and most important race of the entire universe, while fighting the Hashiriyans was not in his original plans.

Sakito makes an offer to Taiya to join the team. Meanwhile, Sakito's partner Byun Diesel is an old acquaintance of Bundorio and wants to meet him again, but Boonboom refuses and the past between them is revealed.

On Tanabata day, everyone is having fun, but only Boonboom remembers his bad past with the word "Milky Way". Then, a new Guruma appears, and Taiya is in the biggest trouble ever...!?

Shirabe is to explain the Boonboomgers to the head of ISA. Meanwhile, Taiya and the others have to fight a familiar Grumer. What's more, something extraordinary happens...!? The 3rd LAP is about to begin.

The Sanseater try to make Mad Rex recover his memories.

As ISA is making suspicious moves, Baisu Maimi, a co-worker of Shirabe, returns to Japan. Meanwhile, the Boonboomger are getting wiped clean.

Society has turned on the Boonboomger, while Yaiyai Yarucar is turned into a Kurumaju with the power of all Kurumaju.