So I've looked at her socials in details, and even found this other account:
https://www.instagram.com/kayuisangma/
I've compared the moles on her belly and chest, they are the same as _.yuyuhan._2.0
For having seen a lot of AI and face filters, this really doesn't look like a fake to me. At least I've never seen an AI able to replicate full body with details such as moles with such consistency. The occasional glitches on her face are probably due to makeup or face reducing filters used by a lot of girls (esp in Asia).
My guess is she made secret accounts (or a manager did) on the side of her main in Taiwan to break into the Western market and make extra money.
Also, if you look at kayuisangma account, she has reels in collab with
https://www.instagram.com/dainty.quinn who is the same girl as
https://www.instagram.com/29__qqq/ who is herself a friend of _.yuyuhan._2.0 . So unless she is also a really sophisticated AI clone (same tattoos, same moles), this is some kind of management that gets JVID Taiwanese girls to do Onlyfans.
Finally, I'm guessing she is lying about being Japanese because it's more "marketable" than Taiwanese to western audiences.
In summary, this is not fake. That's a real account, but that doesn't tell us if OF is worth or just repost from JVID work.