Artist.
Japanese name: δΈε εεΌ₯ ("Ueyoshi Kazuya" or "Ueyoshi kaZUya")
The other name: γγ (Uzu) or εεΌ₯ (Kazuya)
Old name: ζ¨ι εεΌ₯
Site name: Pe5lop!
(The artist also has accounts of Cosplayers-Archive and Koebu. They are unrelated to danbooru, though.)