The Otani surname comes from the fact that the Byodo Mausoleum of Shinran (as mentioned below) was settled on the land of Otani of Kitamon, the north gate of Chionin in Higashiyama, Kyoto.
大谷姓の由来は、後述する親鸞の廟堂が京都東山知恩院北門の大谷の地に定められたことによる。