This is Sakito and Byundi. This is the story before meeting Earth's Boonboomger.
Before Sakito and Byun Diesel return to Earth as seen in Bakuage Sentai Boonboomger's 16th episode, "Purple Settler", we witness this universe-spanning tale of the Settler duo, Sakito Homura and Byun Diesel, before their return to Earth after over a decade of absence.
