was a Japanese waka poet and noble from the middle Heian period. She is enumerated as one of the Thirty-Six Female Immortals of Poetry alongside famous authors, poets, and contemporaries Sei Shà Ânagon and Murasaki Shikibu.
Naishi, as a contemporary and follower of Shà Ânagon, was a lady of the same court in Heian period Japan, and bettered her knowledge of waka poetry through her connection to Shà Ânagon, who was famously known for her waka poetry as well as her novel of courtly observations, . Shà Ânagon was a notorious rival of fellow Immortal of Poetry, Murasaki Shikibu, author of The Tale of Genji.
Her poems are included in the Japanese imperial poetry anthology Shà «i Wakashà «. She also has a personal collection entitled .
At some point in her life, she had a love affair with Major Captain of the Left Asamitsu, writing a poem for him. Of the waka poems she wrote, only three have survived into modernity. Near the end of her life, Naishi took Buddhist vows and withdrew to a temple.
This poem was written in response to a confession of love by Asamitsu, Major Captain of the Left.