In fact, after Zenpo, Nodensho books (secret treatises for Noh theater) written between the late Muromachi period and the early Edo period had the clear features of a textbook or technical guidance book of fleeting and practical nature and were very different from Zeami's and other people's theories of art seeking 'What Noh is.'
事実禅鳳以後、室町後期から江戸初期にかけての能伝書は即物的・実用的な教科書・技術指導書としての色彩が強く、「能とは何か」を問う世阿弥などの芸術論的著作とはかけ離れたものとなっていく。