Nōin 能因 (988-1051?). Japanese poet and monk of the late Heian period. Lay name: Tachibana no Nagayasu 橘永愷. Along with Izumi Shikibu, Nōin is one of " Thirty-six Medieval Poetry Immortals" of waka poetry selected by Fujiwara no Norikane 藤原範兼 (1107–1165).
Nōin authored of the Gengenshu 玄々集 and Nōin's Utamakura 能因歌枕. One of his poems is anthologized in the '' Hyakunin isshu (Poem 69): 嵐吹く 三室の山の もみぢ葉は 龍田の川の 錦なりけり
Arashi fuku mimuro no yama no momiji-ba wa tatsuta no kawa no nishiki narikeri
Blown by storm winds, Mt. Mimuro's autumn leaves have become Tatsuta river's richly hued brocade!