Sa nenu yo wa chiyo mo ari tomo waga seko ga omoi kuyubeki kokoro wa motaji

さ寝ぬ夜は千夜もありとも我が背子が
思ひ悔ゆべき心は持たじ

Roma-ji: Sa nenu yo wa chiyo mo ari tomo waga seko ga omoi kuyubeki kokoro wa motaji
English Translation: Though there should be nights,
even a thousand nights, when
we lie not as one,
a heart that would make you rue
your love I shall never hold
Meaning: Even if a thousand nights should pass without our lying together, I will never hold a heart that would make you regret your love for me.
Commentary: Book Eleven Love Poems Ancient and Modern I 2528

Headnote continued from the preceding poem: "Expressing One's Feelings Directly"
Even if a thousand nights should pass without lying together, she vows never to change in a way that would make him regret having loved her: this is a woman's love poem. Calling the length of the nights apart a grand "thousand nights," she states the steadfastness of her heart plainly, without speaking through any object.
The author is unknown. The anonymous poems of Book Eleven gather love poems by people whose names have not come down to us.

First line, "sa nenu yo wa": "the nights we do not sleep together." "Sa" is a prefix that smooths the rhythm, and the particle "wa" singles out those nights apart.
Second line, "chiyo mo ari tomo": "even if there are a thousand nights." "Tomo" expresses a concessive supposition, and the exaggeration "a thousand nights" stresses how long the separation may be.
Third line, "waga seko ga": "my beloved." "Seko" is a word a woman uses fondly of her husband or lover, marking this as a poem in a woman's voice.
Fourth line, "omoi kuyubeki": "such as would make you rue." The attributive form of the auxiliary "beshi" modifies "heart" in the last line, forming the sense of "a heart that would make you regret."
Fifth line, "kokoro wa motaji": "I will not hold such a heart." The negative volitional auxiliary "ji" closes the poem firmly, pledging an unchanging heart.
Source: Manyoshu
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