Spunky slum kid Astro gets the chance of a lifetime to end the chaos ripping apart his home planet when the playboy prince switches places with him. Now Astro has become Prince Barrage, a boy charged with the duty of restoring peace to the planet...and given an all-powerful magical spear to do it!

In order to save the planet, Astro will have to battle terrifying aliens while learning how to fight from his even more frightening guardian, the exacting knight Tiamat. Does a kid like Astro have what it takes to become the real prince and save the planet?