This show's first season was quite different from the usual Japanese Super Hero as the villians were not robots or monsters, but rather petty criminals who wears a helmet or headgear that had a animal design, which gave them that animals powers, and comitted just petty crimes. They were just career criminals, who in the end gets arrest, just like the super criminal types found in American comic book hero comics ala SPIDERMAN, BATMAN etc (like Dr Octopus, Black Manta, Scorpion, etc). Villians range from purse snatchers like OWL THE THIEF to blackmailers like RAT MAN and his mohawked sidekick MOHICAN, and espionage spy LAVENDER NEWT to gold thief BIG GOLD WARLOCK (who uses his pet snake and even slithered like a snake).
The heros were KAGESTAR (SHADOW STAR) and BELL STAR. They were actually the daughter of a wealthy business man and her friend, who was a shadowpuppettier, who got kidnapped by BEATLEWIZARD for ransom, but escapes, but accidently falls onto a power line, in which for no apperent reason this causes their shadows to take a life of its own, thus becoming KAGESTAR and BELLSTAR (this by the way is the most WEAKEST explanation of someone to get super hero powers in history of Japanese Super Heros). So when in dire need, these two now have the power to summon their shadows to be...KAGESTAR and BELLSTAR (as in 1976 was a popular year for japanese heroes to have fighting female sidekick like KAMEN RIDER STRONGER)! In fact the show even had KAMEN RIDER regular Kobayashi Akiji in atypical role as a bumbling police inspector.
However, superheroes battling petty criminals might not have worked for the children audience, as after the 12th episode, all but 4 of the regulars was written out, and the show became VERY similar to KAMEN RIDER, as the rest of the episodes, they faces DR SATURN, and his Nazi like group, SATURN ARMY.
In fact they were similar to SHOCKER, Kamen Riders old villian, as they had foot soldiers who marches like Nazi's and was Nazi released, had Naya Goro doing the voice of DR SATURN (he did the voice of SHOCKERS big boss), and also used Mutated Beings with monster powers as the monsters of the week, similar to the Kamen Riders Mutant beings. The show then became a decent success as it lasted 35 episodes, but I still prefered the first season where taking on bank robbers like CHAMELEON MAN, as he gets knocked unconscious, as Kobayashi removes his headgear and arrests him. I liked that "realistic" touch. Kind of liked the "U.S comic" touch, as KAGESTARS cape even has U.S star (like Evel Knievel like) on it. BUT if you are a big fan of KAMEN RIDER, be sure to catch the shows last 2 1/2 seasons, as it was VERY similar in style. Fascinating!