[6] Ikkyū presented Jukō with a piece of calligraphy by Yuan Wu (a noted Chinese master of Zen) as a certificate of his enlightenment.

[8] As well as being an exposition of practice, the Kokoro no fumi has been explained as an attempt to establish Japan's merchant class within the field of tea, emphasising as it does the use of Japanese ceramics alongside imported Chinese ones.

[8] For Jukō, excessive concern with the imperfections and rustic aesthetic of Japanese utensils was as bad as a preoccupation with the regular forms and perfect glazes of Chinese ceramics.

[3] Jukō stressed four values in his tea ceremony: kin, a form of humble reverence; kei, a respect for the food and drink; sei, purity of both body and spirit; and jaku, a Buddhist concept denoting calmness and freedom from desire.

[6] He developed the yojohan (four-and-a-half mat teahouse) that was later to become the standard design under Rikyū, changing the tokonoma and creating a more spiritual environment for the ceremony.