The user who made the source tweet is not the original author of the image. They later claimed in a reply it was taken from a unnamed Discord server
https://twitter.com/konoKatushada/status/1812338549028454484

https://www.pixiv.net/artworks/120514715
According to the comments in the Pixiv post, the original artist first posted the image in a QQ group, and then posted a censored version on Pixiv (because the artist was concerned about potentially violating Pixiv’s policies).