Joseph Carter "Joey" Jones, a shy but kind-hearted boy living with his grandmother in Center City, California, works at a coffee shop. Despite financial struggles and school bullying, he maintains a cheerful demeanor. A robotics enthusiast, his greatest desire is to own a premium toy robot known as a Heybo.
Joey and his friend Simon "Psy" Kaina discover a damaged Heybo abandoned by wealthy youths. Joey brings it home and repairs it, eagerly christening the robot Heroman. During the night, lightning strikes Heroman, bringing it to life and causing it to expand to a massive size.
That same evening, Center City faces an assault by Skrugg aliens, who were drawn to Earth after Professor Matthew Denton, an acquaintance of Joey, attempted contact. Joey and Heroman rush to the scene, where they encounter trapped civilians, including Joey’s friend Lina Davis and her father. Using an arm-mounted controller, Joey directs Heroman to employ superpowers to defeat the Skrugg and save the citizens. As the alien invasion persists, this duo stands as the sole barrier between humanity and total destruction.