In Center City on the West Coast, Joey, an orphan living with his grandmother, is captivated by robots, especially the high-tech Heybo. Despite the steep price, Joey's meager earnings from a part-time job hinder his dream of owning one. A chance encounter with bullies mistreating a Heybo leads to Joey salvaging and repairing it, dubbing it Heroman. A serendipitous thunderstorm transforms Heroman into a colossal, patriotic robot obedient to Joey's commands. Meanwhile, in space, the Skrugg aliens plot an Earth invasion, setting the stage for Joey and Heroman to become humanity's unexpected defenders.