Considering that, if memory serves correctly, Kyoko Hinami herself claimed months ago she had no interest in doing a second season so she could pursue a higher acting career (aka: starring in what look to be blatantly sexist films like Princess Sakura) probably hurt Arakawa because he poured a lot of work into growing her character in season one.
This strikes me as a pretty big assumption. I mean... I hate to say it, but Mitsuki is not a particularly well-written or distinctive character. I doubt she was difficult for Arakawa to write, and I think quite a few of her focus eps were actually written by Junko Komura instead.
I don't see why Arakawa would take this more personally than, say, not being able to do more with Kuuga for going on
fifteen years because Odagiri Jou won't have anything to do with Toei. Hinami was at least perfectly willing to come back to shoot new footage for Akibaranger 2's first episode.
His resentment is so clear that he not only writes her out the exact same way that AkibaRed was "written out" in season one, but she is barely even mentioned again until the final episodes.
Why do you think that's resentment? Wouldn't resentment be, "The American soldiers shoot Mitsuki dozens of times and she dies, and none of her friends remember her and no one is sad?" Or she's reduced to a suit-only appearance where a blatantly off sound-alike dies messily doing something stupid? Hell, he could even "disguise" that as a Death of Yellow Four parody.
Her write-out in the beginning of season 2 struck me as very much driven by what Arakawa thought would make sense for the story. If he just wanted to be mean to her, he didn't need to bother with referencing the first season at all. Instead, by having her just leave, he's directly implying that she's a better person than Akagi or Yumeria. (That is, she's capable of genuinely changing her lifestyle, and moving on to bigger and better things.)
Mitsuki's arc was still a work-in-progress and the fact that Hinami gave that up to try and became a by-the-numbers J-idol (like Luna desires to be) just sells me as Arakawa being resentful and creating Luna as nothing more but a shallow, selfish, dumb as bricks punching bag.
But none of the Akibarangers have completed character arcs? That's part of the joke. They're all pretty awful people who balk at growth and change...
just like real otaku. The only character who is a possible exception to this is Mitsuki, who managed to escape the show in order to do something glamorous.
If only one season was planned, then why did the show make such a desperate plea for a second season at the end?
It came off as furthering the joke of the Akibarangers vs Hatte Saburo to me. If they could get a second season, they weren't canceled, and they could keep dragging the show out. Malshina brings this up at the end of S2, actually. Of course, a lot of people did genuinely want a second season, and I'm sure the creators wanted to gauge interest in that before moving on. But honestly, you don't plan a second season when your first one ends with your protagonists destroying the universe. That's the opposite of open-ended.
Except if that were the case, why even bother to mention the fact this rival was related to General Pain/Two?
I'm pretty sure it was to explain why someone so young was referencing an episode so utterly old. Also, it establishes General Pain's boner for Chimera, which turns into a running gag.
Akiba 2 has this issue with rigidly paralleling the structure of the first one for kind of no season. So since Mitsuki's rival was in one episode and then became irrelevant, so does Luna's? But doing that in the middle of the show doesn't work the way it does at the end of a series.
