Midori Yamabuki teaches middle school in Penguin Village, instructing Arale Norimaki after her enrollment. Her original design featured large, curly blonde hair, later altered to brown in the remake. She closely resembles Akane Kimidori, who impersonates her during the Penguin Village Grand Prix for pranks. As a child, Midori wandered from her parents at an amusement park on Metropolis Island and accidentally boarded a private spaceship owned by the childless royal couple of Planet Takeya-Saodake. King Saodake and Queen Takeya adopted her. Years afterward, they located her biological parents and returned her to Earth, though she vowed to inherit their throne if they became elderly or infirm. Senbei Norimaki persistently pursues her romantically, resulting in mishaps: X-ray glasses aimed at her cause a scooter crash; skirt-lifting chain reactions fail; an alien ape kidnaps her during a space date, nearly devouring her until Senbei accidentally shrinks her into an ant and steps on her before reversing it. He also plants a camera in Arale to spy on Midori bathing, thwarted by Arale’s poor vision. Midori overhears Senbei mutter "Will you marry me?" while delivering carrots to his home and joyfully accepts, prompting an immediate wedding. Cat-like creatures interrupt their honeymoon, kidnapping Midori as a sacrifice to a giant ape. Stripped naked and bound in a cooking pot, she is rescued by Senbei, Arale, and Gatchan. Post-rescue, she observes Arale battling a caveboy before returning to Penguin Village. Post-marriage, she adopts the Norimaki surname, becoming a surrogate mother to Arale. She births a son, Turbo, and later a daughter, Nitro. Her personality grows more scatterbrained and ditzy but remains fundamentally kind. In crossovers, she bakes cookies for Goku during his Penguin Village visit and witnesses Arale defeat General Blue.