Kozuki Mai is an elementary student who wants to be a magician and perform in her family's "Magicarat" magical act; however, she is too young, and her magic skills are not very good. Then one day, she encounters a ball of light that was put into a stuffed doll of flying squirrel, bringing it to life and somehow giving her the power to turn in to the 18-year-old magician "Magical Emi." As Emi, Mai was able to join the magic act. But she must keep her identity a secret from her family and from her crush.

October 1941, as the second World War threatens to destroy the civilized world, an unforeseen complication suddenly occurs. An alien invasion! Despite the sudden appearance of these extraterrestrial aggressors, the Axis and Allies continue their destructive conflict. Only the Kishin Corps and their giant Geo-Armor Robots (a.k.a.: Kishin), developed from a captured alien robot soldier, stand between the Earth and total annihilation! A teenager, named Taishi, suddenly finds himself at the center of a struggle over a mysterious black attaché case entrusted to him by his father, Professor Tokamura. The case contains the controlling mechanism for one of the giant Geo-Armor Robots, and the Japanese Kanto Army, the alien invaders, and the Kishin Corps all want to recover the device! Between the spies, the armies, the aliens, and the Giant Robots, Taishi is in for an epic adventure—if he can survive it!

An animated pilot film for Ninja Bugei-chou released to the public over three decades later on Ninpuu Kamui Gaiden DVD volume 7. The pilot film was created in 1969 as director Nagisa Ooshima was wanting to make a TV animation to build off his controversial film from 1967. The pilot was rejected by Shirato himself (the original comic creator the film was based on) and the plan was changed to animate Ninpuu Kamui Gaiden instead, a side story to the Kamui Den manga also created by Shirato. Though with this change, Ooshima did not partake in Ninpuu Kamui Gaiden's production.

Mike is a penguin soldier who returns home after being injured during combat. Estranged from his family and friends, he leaves his hometown and starts to roam adrift through the country.