Wyatt Bernstein is reluctantly taken to a Build-A-Bestie store for his birthday and, while there, creates a boy-filled version of a Bestie, a puppet he names Crash, who comes to life as the brother he always wanted. Crash brings Wyatt some much needed "boy reinforcement" amidst a household of sisters - Amanda, Cleo and Jasmine, and helps Wyatt come up with a plan to get his own room. But, Crash's plan soon backfires, jeopardizing the relationship with his new brother.