Johnny Sokko and His Flying Robot

X-7: A Mysterious Enemy Agent (1x18)

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One night, a huge balloon lifts away a big building in the Ginza. Unicorn receives a challenge letter from a mysterious man who calls himself X-7. Johnny Sokko soon discovers that he and X-7 have more in common than anyone knows...and that he must do battle with X-7, who is now operating the Giant Claw!