It only comes as a pmx file so you'll have to do some converting if you wanna use it elsewhere but here you go. Comes with a few different outfits attached to the model as well, such as a bunny suit and swimsuit.
I did also see this Koharu model while I was looking, though I don't have it. Seems to be usable with vrchat as-is though, so figured I'd link it here too if anyone was interested.
https://www.melonbooks.co.jp/detail/detail.php?product_id=1747988