Toei had originally planned for Captain America to star in Battle Fever J with a group of newly created Captain characters from other nations, like Captain France and Captain Japan. However, in 1978, Captain America’s live action film rights were tied up with Universal Television, which was making TV movies starring Reb Brown (which Conan O' Brien used as a joke). The golden-age Marvel heroine Miss America was drafted as his replacement. The rest is history but how much did Battle Japan have in common with Captain America?
Captain America was a skinny young man who was genetically altered to be an All-American Hitler smashing superhero. Battle Japan was a former National Defense Ministry officer. He is good at judo and karate. He is armed with a spear. He does a kung fu dance. Battle Japan never changed his body and wasn't from the past (well in the contents of the show when it originally aired). The first Miss America in BFJ was an FBI agent who joined the Fever team to avenge her father Bosner, who was slain by Egos. She is armed with throwing knives. After she was wounded by the Dracula Monster, she returned to the United States. The first Marvel Miss America, a teenaged heiress whose uncle was sponsoring a scientist who claimed to have gotten superpowers through a device that had been struck by lightning. Joyce, secretly tampering with the contraption during a thunderstorm, herself gained the ability to fly and great strength after lightning similarly struck (she originally had superhuman strength, as well as other powers, but after her few early appearances they were retconned).