Wyatt Bernstein is a 12-year-old boy who desperately wants a brother to offset having older sisters Amanda and Cleo, younger sister Jasmine, and mum Mel. As a typical tween boy, Wyatt likes hanging out at the arcade with pal Pesto, but he also wants someone to do 'guy stuff' with at home. When his family takes him to a Build-a-Bestie store for his birthday, he creates a boy-filled 'bestie'. Little does he know that it will fulfil his wish of having a brother, though not a human one. The stuffed puppet named Crash comes to life, finally bringing the longed-for brotherly figure into Wyatt's life. Yet it is not all positive for Wyatt, as Crash introduces chaos into the boy's life and inadvertently disrupts his relationships at home and school. Through it all, Wyatt discovers what it means when someone new enters your life and turns it upside down.