Gusai (the Renga master) (救済 (連歌師))
To acquire proficiency in waka, he learned the poetic style of Tamesuke REIZEI, and to master Renga, he studied the techniques of Zena. He collaborated with Yoshimoto NIJO to compile a Renga anthology called the 'Tsukuba shu' in 1356, and in 1372 he established the rules for composing Renga and set them down in the 'Oan shinshiki' (The New Form of the Oan era). He did not favor any specific style for the manner of writing verses in his poetry, and is instead considered to have excelled in achieving delicate word-play and true depth of feeling, and in his tsukeku (seventeen-syllable linking verse) a sense of artistic tension. In addition to his main pupil Yoshimoto NIJO, his disciples (pupils) included Shua, Eiun,, Soa, and Ria, and Sadafumi's poetic style also influenced the development and spread of Renga circles in the early Muromachi period.
In addition to the poems of his in the 'Tsukuba shu,' his poetry was also included in the 'Bunwa senku' (One Thousand Verses from the Bunwa era), the 'Murasakino senku' (One Thousand Verses from Murasakino (the Purple Fields)), and the 'Jiko shua hyakuban renga awase' (The Jiko Shua's hundred-verse Renga contest).