It's hard to say for my own writing really. Tone in writing is something I struggle to understand myself and I feel like as a result everything I write ends up reading the same way, even if they should theoretically end up not being that (compare an average Gwen post with an average June post, that's what I mean).
But maybe this is me misunderstanding the question, which is pretty embarrassing considering I prompted it. I had said I reading Avril's post as giving me feel good shoujo feelings, and my reasoning for that was just her character, being a teenage girl figuring herself out and is into all things pink and girly, which is perfect for a Precure protagonist or something. And y'know, the whole baby romance thing definitely plays a role with that, and her being heavily associated with the color pink and flower. So with that being said, I guess what I said above is a fucking lie because for example, Gwen's story reads like a shounen battle manga since she's beat-by-beat a shounen protagonist in a Pokemon journey story. June meanwhile is... well I'm not 100% sure, somebody else put it into words for me honestly, you won't receive a reward but I'll be mildly pleased for a very brief moment which should be enough of a reward as it is.
I will say "tone" is not an easy concept for me either and, you're also right in saying that the character traits one may be working with contribute a lot to it. Avril's story sure might have hit different if she was, say, a goth... every potential reference is entirely accidental haha.
I also need to say that this was rather new to myself as well, up until that conversation you mentioned. I didn't really feel like I was giving Arianne or Avril a different vibe when writing, but you can tell there's some difference, and it's mostly because of themselves as characters and what they go through, sure. But also of how we end up conveying their feelings and writing about what they do -
that also changes slightly. Arianne's reflective moments feel a bit different than Avril's~
And so yeah, from there comes the idea that reading Avril feels more like reading a shojo, like you said, and reading Arianne posts (if I can write them well and mantain her character) turn into shonen action stuff quite seamlessly. But it's also true that neither of them is meant to feel that dark or serious to read compared to, say, what I was foreboding for Helene back in Tocker, or some of the posts I'd like to try out for Evelyn.
This brings me to the other question - consistency in a roleplay. I'm not sure if it's something I do deliberately but it feels like I tend to adapt automatically my writing to what I feel the roleplay is about and to what other people are doing. In fact, it's helpful to already have some indication of this when joining a roleplay, to make a character that just
works well there. As much as I planned for Avril's story to involve personal moments and difficult choices, I know I would've been likely to write them differently than how I did in Hoenn Square 1, if Avril happened to be part of Spear, for example.
I will admit it's a bit of a complicated topic - but even I'm not sure what I was on when I made it this morning, I feel like I was still onto something. There's potential to talk about this!