Narihira was known as a great lover; a third of his poems included in the Kokin Wakashū (Kokinshū) describe his various romantic affairs, and after his death the national history Nihon Sandai Jitsuroku (compiled 901) said of him: "Narihira was elegant and of handsome appearance, but he was unrestrained in his self-indulgence."

The Tales of Ise portrays Narihira as falling in love with Fujiwara no Takaiko, a consort of Emperor Seiwa, and it is hinted that this was one of the reasons for his leaving the capital and travelling east.
It has been speculated that this romantic affair with the consort of the emperor was the reason why the Sandai Jitsuroku describes his rank as going down from Junior Fifth Rank, Lower Grade to Senior Sixth Rank, Upper Grade, before again rising to Junior Fifth Rank, Upper Grade the following year.
However, it has also been speculated that this may be an error in the Sandai Jitsuroku as a result of binding changing the order of events.
Furthermore, Fujiwara no Takaiko reputedly had an affair with the monk Zen'yū (善祐), which may have formed the core of the otherwise fictional legend that she also had an affair with Narihira.
Whether the affair was historical or not, the Reizei family's commentary on The Tales of Ise speculates that Emperor Yōzei was a product of this union, and not the previous emperor.

One of Narihira's most famous affairs—the one that gave The Tales of Ise its name—was said to be with Yasuko, high priestess of the Ise Grand Shrine and daughter of Emperor Montoku.
The Tales of Ise describes the protagonist, presumed to be Narihira, visiting Ise on a hunt, and sleeping with the priestess.
However, a passage in the Kokinshū describes the meeting ambiguously, in a manner that implies Narihira did not sleep with the priestess herself but rather another woman in her service.
The 12th-century work Gōshidai (江次第) and the 13th-century work Kojidan claim that the product of this union was Takashina no Moronao (高階師尚), who was later adopted by Takashina no Shigenori (高階茂範).
Japanologist Helen Craig McCullough stated there was "no evidence" the affair between Narihira and Yasuko was "more than a romantic myth".

A headnote to poems 784 and 785 in the Kokinshū connects Narihira to the daughter of Ki no Aritsune.
Medieval commentaries call her Narihira's wife, and some modern scholars, such as Katagiri, do the same, although the only early source that explicitly names her is the note in the Kokinshū.
 In the classical Noh play Izutsu, an adaptation by Zeami Motokiyo of "Tsutsu-Izutsu" from The Tales of Ise, portrays Narihira and Ki no Aritsune's daughter as childhood playmates who eventually marry; Narihira is unfaithful to his wife, and her pining spirit appears to a monk after their deaths.

It has been speculated, based in part on their being considered the most beautiful man and woman of their age, that Narihira and the poet Ono no Komachi may have been lovers, but there is little evidence for this.
Scholars of the 20th century such as Makane Sekitani (関谷真可禰, Sekitani Makane) have held up this speculation, which can be traced back at least as far as the 14th-century historian Kitabatake Chikafusa.

Chikafusa likely used Kamakura period Kokinshū commentaries such as the extant Bishamondō-bon Kokinshū-chū (毘沙門堂本古今集注), which speculates that one of Komachi's poems was left for Narihira after a tryst.
The Bishamondō-bon Kokinshū-chū in turn likely worked from a then-common belief that fictional Tales of Ise was a genuine historical work detailing the actual events in Narihira's life (see above).
Kamakura period commentaries on The Tales of Ise therefore tried to insert the names of real women where the original text simply said "a woman", and thus inserted Ono no Komachi into several passages of the text.

The literary scholar Yōichi Katagiri concluded, on the lack of surviving evidence, that, while it is possible that Narihira and Ono no Komachi knew each other and were lovers, there was no usable evidence to say conclusively either way.
Narihira was known as a great lover; a third of his poems included in the Kokin Wakashū (Kokinshū) describe his various romantic affairs, and after his death the national history Nihon Sandai Jitsuroku (compiled 901) said of him: "Narihira was elegant and of handsome appearance, but he was unrestrained in his self-indulgence."
The Tales of Ise portrays Narihira as falling in love with Fujiwara no Takaiko, a consort of Emperor Seiwa, and it is hinted that this was one of the reasons for his leaving the capital and travelling east. It has been speculated that this romantic affair with the consort of the emperor was the reason why the Sandai Jitsuroku describes his rank as going down from Junior Fifth Rank, Lower Grade to Senior Sixth Rank, Upper Grade, before again rising to Junior Fifth Rank, Upper Grade the following year. However, it has also been speculated that this may be an error in the Sandai Jitsuroku as a result of binding changing the order of events. Furthermore, Fujiwara no Takaiko reputedly had an affair with the monk Zen'yū (善祐), which may have formed the core of the otherwise fictional legend that she also had an affair with Narihira. Whether the affair was historical or not, the Reizei family's commentary on The Tales of Ise speculates that Emperor Yōzei was a product of this union, and not the previous emperor.
One of Narihira's most famous affairs—the one that gave The Tales of Ise its name—was said to be with Yasuko, high priestess of the Ise Grand Shrine and daughter of Emperor Montoku. The Tales of Ise describes the protagonist, presumed to be Narihira, visiting Ise on a hunt, and sleeping with the priestess. However, a passage in the Kokinshū describes the meeting ambiguously, in a manner that implies Narihira did not sleep with the priestess herself but rather another woman in her service. The 12th-century work Gōshidai (江次第) and the 13th-century work Kojidan claim that the product of this union was Takashina no Moronao (高階師尚), who was later adopted by Takashina no Shigenori (高階茂範). Japanologist Helen Craig McCullough stated there was "no evidence" the affair between Narihira and Yasuko was "more than a romantic myth".
A headnote to poems 784 and 785 in the Kokinshū connects Narihira to the daughter of Ki no Aritsune. Medieval commentaries call her Narihira's wife, and some modern scholars, such as Katagiri, do the same, although the only early source that explicitly names her is the note in the Kokinshū.  In the classical Noh play Izutsu, an adaptation by Zeami Motokiyo of "Tsutsu-Izutsu" from The Tales of Ise, portrays Narihira and Ki no Aritsune's daughter as childhood playmates who eventually marry; Narihira is unfaithful to his wife, and her pining spirit appears to a monk after their deaths.
It has been speculated, based in part on their being considered the most beautiful man and woman of their age, that Narihira and the poet Ono no Komachi may have been lovers, but there is little evidence for this. Scholars of the 20th century such as Makane Sekitani (関谷真可禰, Sekitani Makane) have held up this speculation, which can be traced back at least as far as the 14th-century historian Kitabatake Chikafusa.
Chikafusa likely used Kamakura period Kokinshū commentaries such as the extant Bishamondō-bon Kokinshū-chū (毘沙門堂本古今集注), which speculates that one of Komachi's poems was left for Narihira after a tryst. The Bishamondō-bon Kokinshū-chū in turn likely worked from a then-common belief that fictional Tales of Ise was a genuine historical work detailing the actual events in Narihira's life (see above). Kamakura period commentaries on The Tales of Ise therefore tried to insert the names of real women where the original text simply said "a woman", and thus inserted Ono no Komachi into several passages of the text.
The literary scholar Yōichi Katagiri concluded, on the lack of surviving evidence, that, while it is possible that Narihira and Ono no Komachi knew each other and were lovers, there was no usable evidence to say conclusively either way.
Ariwara no Narihira