Kei Sanbe
Circle: NO-ZUI MAGIC (脳髄魔術)
Kei Sanbe was previously an assistant to Hirohiko Araki.
There was a rumor floating around that he and fellow illustrator Kanesada Keishi (兼処敬士), with whom he shares his site, are siblings; but no actual blood relation exists. He currently resides in Chiba, Hokkaido.
According to the omake section in the last volume of Mouryou no Yurikago, Sanbe Kei and Kanesada Keishi are husband and wife.