Toshiyoris Poetic Essentials (俊頼髄脳)
"Toshiyori Zuino" (Toshiyori's Poetic Essentials) is a book with essays on tanka poetry written by MINAMOTO no Toshiyori. Considered to have been completed in 1113, it is also called "Toshiyori Kuden" and "Shunbisho."
Commissioned by FUJIWARA no Tadazane, it was written for Toshiyori's daughter as a guidebook on poetic composition.
The book provides detailed accounts on how waka poems are created, though it reads as a collection of anecdotes without structural coherence.