Hashino Mizuha is the artist for this game and also a vtuber, she has Aliceincradle gamedev vids on youtube. Her avatar is drawn by Kuroba (artist for magic of stella) according to her Twitter.
But me and previous commenter believe they are the same person. You can look at Kurobas pixel art and her previous nswf art on danbooru to see the similarities to the art in this game.