Mahoujin Guru Guru

Mind you that the actual phrasing of that tweet
twitter.com/aho_boy/status/943158158880530433
is that as a project, it's properly in the black and a proper "success".
That could mean anything from "we broke even" to "we're leaving Kemono Friends in the dust" (I expect it to be closer to the former than the latter). Whether it's considered to have sold "well" depends on the expectations of the money pushers and whether a sequel will be made will depend on whether they can be convinced that this "success" can be reproduced.

Jisan was not "semi" main cast. He was the full-blown third protagonist.

Why is she called Cool J?

For the entire old man's section.
>Title: The Beginning of a Legend
>Kita: I'm thinking of going on a journey to find a successor to the Kita Kita dance.
>Nike: Then see you later!
>Kukuri: Stay safe.
[A light farewell]
>Kita: You can call me anytime you're in a pinch!
>Kukuri: [Nervous Laughter]
>Kita: Now then,
>Kita: be well, you two
>[Title Crawl]
>Nike: Why did the title change!?
I swear, if it's an Oyaji anime before a season two.

What is the Kita Kita manga even about?

youtube.com/watch?v=taV3l3XoJVA
youtube.com/watch?v=kffgN7Fgyxk

Is there any doubt?

cute

I somehow want and don't want a Kita Kita spinoff anime at the same time.

At least the old man isn't the only protag.