Artist. Formerly tagged as ryu56.
Japanese name: 神沢 零司 (Kamizawa Reizi)
(Danbooru's official romanization of 零司 is "Reiji". But Kamizawa does not want this pen-name to be spelled that way)
Circle name: "SARK" (サーク) or "SARK-um" (サークユーエム)
Site name: アルティマニア