The team collaborates with YouTuber HIKAKIN at a race track Taiya purchased, only to be plunged into a crisis. Princess Nicola of the "Sensing Star Trickle" flees to Earth, pursued by the Hashiryan captain Demon Thunder. The villain transforms the circuit into "Circuit Gurumer" and threatens to destroy Earth, forcing the Boonboomgers to rescue the princess and recover their stolen Boonboomcars. 

Jou is training baseball with some children when the Hashiriyans attack them and an enraged Jou challenges the villains for a match, dragging the entire team, including Bundorio, Byun and Shirabe on it.