The Strange Birthday Present

S1 E37: On his most recent birthday, Astro Boy received an amazing gift, something he had always wanted... a little sister! She was a gift of Doctor Packadermus J. Elefun, head of the Institute of Science, and she was the image - the very image - of Astro Boy, but with pigtails. Her name was Astro Girl. A guileless child, in effect “born yesterday,” Astro Girl somehow found herself in the clutches of an eccentric inventor who had perfected a method of doubling things. In no time at all, there were two Astro Girls - each identical to the other. Not even Astro Girl herself could recall which was the original, and which the duplicate. When one Astro Girl became enmeshed in a shady plot to exploit her talents (which were nearly as formidable as Astro Boy’s,) it took the other Astro Girl, plus Astro Boy, plus the entire Institute of Science to determine which Astro Girl was involved and how to save her!