"Jizou" is the guardian deity of children. "Kurabo" is a japanese way of saying "club". So another way of saying it is "Guardian Deity of Children Club".

The only thing confirmed to be Jizou Kurabo's work this far is Valis II for the PC-Engine, and the two tracks from the game on the Valis II soundtrack.

It's pretty obvious, looking at the liners of Valis II, that Hisao Inoue is a member of this mysterious club.