Astro Boy longs to have parents, so Professor Ochanomizu has robot parents custom made. In a robotic factory, an experimental robotic named Frankenstein (Colosso) goes haywire and escapes. Frankenstein becomes the slave of a gang led by Acetylene Lamp (Big Boss), who has Frankenstein steal from a safe, a ballet, and a bank. Astro is blamed by Inspector Tawashi (Inspector Gumshoe) for the crimes, but is saved by Professor Ochanomizu. Professor Ochanomizu devises a plan to bait Frankenstein onto a ship using fake diamonds, where Astro defeats Frankenstein. The mobsters arrive, but Astro defeats them and they are soon arrested. Astro is rewarded for his heroism with his recently completed parents. Frankenstein is repaired.