@cqi @ceruds @nugger This appears to be the artist: https://twitter.com/Aragon_Honnin and https://www.aragondayo.com/ in case Twitter does a purge.
Is industrious, Google Translate of the second line of the Twitter bio which is confirmed by various pictures and postings is “Currently, I am making original figures with overseas toy makers.”
Yes, there’s an interview about it at https://akiba-souken.com/article/49282/ - it seems that the illustrator’s wife decided to model his illustrations in clay and make little GKs out of them, which lead to them both dabbling in 3D printing and resin figure casting. They even wanted to try putting them in blister packs like “American figures”, so they went to the Mandarake labyrinth in Nakano Broadway to study some of the old American toy imports so they’d be able to get it right.
After they sold a few of their doujin-level figures at WonFes 2019, it seems they got international attention via social networks and were contacted by a Chinese toy maker, who now manufactures and sells their stuff. Good for them!