Mira Shifuto's about to get married to a man she doesn't want to when she's suddenly whisked away by a deliveryman.

Ishiro still won't acknowledge Mira as a Boonboomger as the team has to deliver classified documents to a foreign ambassador.

Mira goes out on her first solo delivery while a clock-themed Hashiriyan tries to stop everything that moves.

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.

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.

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.

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

Genba is defeated by Dissrace and rescued by Sakito when they run into a mysterious man on the railway tracks.

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.

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

A boy who admires Bun Blue appears and asks to become his apprentice. However, Ishirou does not want any part of it, leaving the situation to Bun Black instead.

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.

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.