Sounds cute but I worry the idea is a bit too clean and modest, we are a lewd/NSFW fetish board after all, and I'd want our OC to get some actual artwork, and doing that requires some sex appeal or cuteness. Some level of popularity would be nice so people would be willing to draw our OC.
I'm not sure if you're aware of Amane (I think that was her name), the -tan for Torrential Downpour, it was a niche thing admittedly, but the sheer lack of artwork for her and the fact that she was basically forgotten about is kind of a shame, and your idea reminds me of her's, even though I like it.
Its a good character to be sure and certainly plenty workable for some fun size scenarios, but I'm not sure how well it would work out for a board mascot who we would want to have some OC/drawings done at some point in the future, and to draw people in.
Maybe it might work better if her outfit was made a bit less... traditional and more sexy or something that would reach out and grab people in some way, but its hard to say.
A miko/shrine maiden idea in general sounds fun though. I have a preference for the red hakama and tabi socks myself.
A lot of the time simpler is usually better for these kinds of things (even if I often might have a preference towards the flashy/maybe overdesigned stuffs myself) so that's not a bad idea to keep in mind.
I wouldn't mind multiple board-tans (personally I was even thinking of the possibility of our board-tan having a family of sorts as a potential idea but I digress)
but let's be careful .about bloating things too much to start with
2 characters like the ones you described might work. Superheroes are pretty iconic and recognizable, appropriately flashy and attention-grabbing too.
Pretty nice outfit choice as well from what I'm seeing.
>Kaiju girl who considers herself the queen of the earth
>erotic/destructive slapstick bretty cool.
This feels like a /sp/ shitpost.
Softball uniforms can be hot at times but it'd be too easily confusing to people and shit imo.
Certainly worth considering at least, some of these are bretty cool.
Animal print clothing is a fun and sexy idea.
It almost makes me think of oni girls like bakugeki's, which are bretty fun.
Idea is okay too.