Hello, it's me, longtime vocal synthesizer enthusiast who usually sticks to the sidelines, but this is a level of grossness that I just have to talk about and get it out of my system. And because the problem here goes a lot deeper than just this character or company.
So, an underage interactive sexbot character being developed for one of the major commercial vocal synth platforms is certainly the worst- or at least, most egregious- instance of the sexualization of minors in this space, or subculture, or whatever you want to call it; but it didn't just come out of nowhere. In fact, it was probably inevitable, as long as character-based vocal synths continue to be heavily associated with, dominated by, and primarily marketed to moe otaku.
Moe otaku culture, and by extension a huge chunk of modern anime culture, is in large part built on top of a foundation of systemic sexual objectification of underage girls. It's not just that "lolicon" is popular among a distressingly large number of anime fans, or even that it's as normalized as it is. It's that almost every popular moe design trope, character archetype, cliche or convention can directly trace its lineage back to (often very explicit) lolicon artwork. It's that a lot of successful and well-respected creatives have created, or still are creating, explicit works featuring children. Even some of the ones not creating it are still actively consuming it.
There's a fantastic article released last year that dives into this a fair bit, and is probably the best resource for this stuff that isn't written in Japanese. I highly suggest reading it as long as you aren't too easily disturbed by the subject matter.
Not one part of moe otaku culture is free of this, including the character-based vocal synths popularized by Hatsune Miku. Now, aside from some of her design traits being descended from lolicon archetypes, namely the school uniform, pigtails, thigh-high socks, and just the fact that she's a beautiful, idealized 16-year-old girl; Miku herself is pretty wholesome. In fact I'd say that a lot of people who like these traits (I'd like to think most of them, but I don't know if I should be that optimistic) probably do so for completely innocent reasons. Especially outside of Japan, where cultural differences often mean we over here don't pick up on what the artist intended to communicate. Inside Japan, where most of this content originates, is a very different story though.
Lolicons are EVERYWHERE in Japanese vocal synth community, on both the creative and consumer sides. It's so deeply embedded it's almost unbelievable, if you're not expecting it. One of the very first UTAUs created, available for download on the official UTAU website, is named Loline Com. Likewise, one of Sharpkey/DeepVocal's test vocals is literally just named "loli". (I also thought SynthesizerV had a test voice named loli but I can't find it on the wiki, so I might've just confused it with DeepVocal.) Companies sell body-pillows of their underage characters, even PRETEEN CHARACTERS like Otomachi Una and Tohoku Kiritan, who are both ELEVEN YEARS OLD! Just... everything surrounding Kiritan in particular is absolutely disgusting, again from both her creators and her fans. I had to stop following the official Zunko Twitter because, not only would they not stop retweeting nasty fanart of Kiritan; they eventually posted concept art of the Tohoku sisters as little kids, which was actually really cute at first! Until I noticed they were tagged "Loli Day".
Just from some quick term searching on Twitter, English tweets about Fee are almost universally about how disgusted they are by it and how they're disappointed that CeVIO is even allowing this; while Japanese tweets about it are just like, "Oh look, new character! How cute!" And this is pretty much how I expected it to go, based on my experience in both sides of the fandom. (I know a bit of Japanese, and auto-translate helps too, I'm not completely flying blind). I did see one tweet obliquely mention "overseas controversy" about her, with the implication being that even though a market for vocal synths exist in English-speaking countries, Japanese creators might do best to just ignore us whiny westerners and continue to cater to their insular little community of perverts with too much money so that they can enjoy their underage sex objects in peace.
It's honestly really disheartening. One of the reasons I even started learning Japanese in the first place was because I wanted to communicate with fans from over there, see what it's like, but all I found was... this. And it's not just vocal synth fandom, Japanese Digimon fandom for example also has its fair share of normalized gross shit, but it's a whole different level with synths because the creeps are basically the main demographic. It just really sucks, because I love vocal synthesis and think it's a fascinating technology with immense creative potential, but it's been so closely linked to moe loli idol culture garbage for years now that I always feel a little gross whenever I think too much about it.
I feel like Fee might end up causing something of a rift between Japanese and overseas synth fandoms. This kind of stuff has been bubbling just under the surface for a very long time now, but most Western fans either haven't noticed or just chose to look past it. Fee comes as a shock to us over here, but in Japanese fandom, it's kinda just assumed that underage sexualization is the norm and this company is just the first one to really monetize it in this space. Because that's how moe/loli/idol/otaku/etc. culture is, and anyone who speaks out against it is just making trouble where there doesn't need to be. Everyone in this thread asking "Why does she have to be 17? If you want to sexualize her, why not just make her an adult?!" doesn't seem to get that her being a child is a major selling point.
I really, really hope that Solaria does well, and with her we can start to move away from moe synths, because "moe" is built on a rotten foundation with little worth preserving. I'm not saying we should go back to Leon and Lola-style faceless synths, characters are fine, I love characters! But maybe we have enough pigeon-toed doe-eyed little teenage girls for... the rest of time maybe? Like, we have enough of those, especially ones aimed at adult men. Maybe we can try something new, spread out a bit.
I love vocal synthesis, it's an amazing technology with some incredibly skilled users and a fascinating culture that's sprung up around it, and I don't want the scene to be overrun by the creeps. They don't deserve it.