Ejin 研究所 ((Ejin Kenkyuujyo) (meaning Ejin Laboratory) is a doujin circle, an amateur publishing group in Japan. They say they started by launching a PC adventure game and formed their coterie circle in order to make the simulation game. Now they have produce a main card game. They have also produced a pen-and-paper RPG.
It is their motto to make a "more interesting game appear and do so while drinking".