You might have noticed that there was another Tsuburaya product besides Ultra Series titled “Kaiki Daisakusen” in the list of the products broadcast in Takeda Hour.
Kaiki means something bizarre or horror; Daisakusen means big operation.
I assume that the title itself is not so significant, though.
It’s a Tsuburaya product just after “Ultra Seven.”
It has no superhero like Ultraman or Ultra Seven appear with no monsters and no defense team.
It’s a story to depict the activity of SRI (Science Research Institute) standing up against “scientific crimes” brought about by humans.
It was produced on the assumption that Kaiju Boom was already over because of the lowering viewer ratings “Ultra Seven” got.
The producers are likely to have thought Kaiki Boom was coming next because anime products featuring kaiki were getting popular at the time.
I bet “Kaiki Daisakusen” was an ambitious product featuring SFX as expected from Tsuburaya Productions with the name of Eiji Tsuburaya credited as supervisor just like the preceding Ultra Series (Kuuso Tokusatsu Series).
And it seems to have gained decent popularity, and it’s still highly valued among fans now.
But, as an ardent fan of First Trilogy of Ultra Series, it was so sad not to be able to see Ultra heroes and Ultra monsters any more.