Maigetsusho (The Monthly Commentary) (毎月抄)
Maigetsusho (The Monthly Commentary) is a treatise on waka poetry written by a kajin (waka poet) FUJIWARA no Teika in 1219.
It is a style in which someone asks Teika to correct a waka, and Teika teaches him while preaching 10 types of waka rules of behavior (the ushin (sentiment with artistic sensibility) style, the Yugen (the subtle and profound) style, style with concrete meaning, balanced and harmonious style, elegant style with sense of tension and neatness, style with distinct visual depictions, intellectually artful style, style with uncommon idea, complicated and skilled style, and strong and sharp style), among which Teika especially placed importance on the ushin style.