Yomi
Yomi is ruled over by Izanami no Mikoto, the Grand Deity of Yomi (Yomotsu-Ōkami 黄泉大神).  According to Kojiki. The entrance to Yomi was blocked by Izanagi when he returned to Earth, using a great boulder (Chibiki-no-Iwa 千引の岩) at the base of the slope that leads to Yomi (Yomotsu Hirasaka 黄泉平坂).