I design them and my artist makes them based off the design briefs and references. All the work is human art and nothing is AI.
Her handle is Zuttecita, here's a link to her portfolio if you want to follow her. You can also find her on deviant art under zutte-chan.
https://lemmasoft.renai.us/forums/viewtopic.php?t=68731&sid=ab914fddf56892544a9f...