After the defeat of their old arch nemesis, The Shredder, the Turtles have grown apart as a family. Struggling to keep them together, their rat sensei, Splinter, becomes worried when strange things begin to brew in New York City.
Set in the futuristic Metro City, Astro Boy (Atom) is a young robot with incredible powers created by a brilliant scientist in the image of the son he had lost. Unable to fulfill his creator's expectations, Astro embarks on a journey in search of acceptance, experiencing betrayal and a netherworld of robot gladiators, before returning to save Metro City and reconcile with the father who rejected him.