In the Otogizoshi , a collection of Japanese prose written in the Muromachi period , Tamamo-no-Mae was a courtesan under the Japanese Emperor Konoe . In the OtogizÅ shi , a collection of Japanese prose written in the Muromachi period , Tamamo-no-Mae was a courtesan under the Japanese Emperor Konoe ( who reigned from 1142 through 1155 ) .