It has been said since ancient times that Emperor Kazan selected the poems himself, or he ordered FUJIWARA no Nagato (or Nagayoshi) and MINAMOTO no Michinari to select them, but there is no positive proof.
古来、花山天皇の親撰もしくは院が藤原長能・源道済に撰進させたといわれてきたが、確証はない。