classic waka stream

はかなしやさても幾夜か行く水に
数書きわぶる鴛の独り寝
Roma-ji

Hakanashi ya satemo ikuyo ka yuku mizu ni kazu kakiwaburu oshi no hitorine

English Translation
How vain it is!
For how many nights, then,
on the flowing water
does it strive to write the count—
the mandarin duck sleeping alone?
Meaning
How futile it is! For how many nights, I wonder, has the mandarin duck, sleeping alone, tried in vain to tally its lonely nights, as if writing numbers on flowing water?
Commentary
Book Six Winter Poems 652

Headnote: "When I presented fifty poems."
This is the first poem of the waterfowl sequence. It sings of a mandarin duck that, with the futility of writing numbers on flowing water, strives in vain to count its nights of sleeping alone. According to the headnote, it was composed when a set of fifty poems was presented.
The author, "Masatsune," is Fujiwara no Masatsune. A son of the Minister of Justice Fujiwara no Yoritsune, he founded the Asukai house of kemari football and poetry. He was one of the compilers of the Shin Kokin Wakashū.
The scene is a winter night, and the place is a river where mandarin ducks float.
The direct occasion is the presentation of a fifty-poem set. The headnote does not record for which gathering the fifty poems were composed.
"Writing numbers on flowing water" draws on the anonymous Kokin Wakashū poem "Yuku mizu ni kazu kaku yori mo hakanaki wa omowanu hito o omou narikeri" (More futile than writing numbers on flowing water is loving one who does not love you), and is used as a figure for futility.

The first line, "hakanashi ya," means "how futile," with "ya" as an exclamatory interjectory particle. The poem breaks after the first line.
The second line, "satemo ikuyo ka," means "for how many nights, then?" with "ka" as an interrogative particle.
The third line, "yuku mizu ni," means "on the flowing water."
The fourth line, "kazu kakiwaburu," means "struggles to write the count," with "wabu" adding the sense of failing and fretting. Just as numbers written on flowing water vanish at once, counting the nights of sleeping alone is futile. The attributive "waburu" stands as the close answering the particle "ka."
The last line, "oshi no hitorine," closes on a noun: the mandarin duck sleeping alone. Mandarin ducks were held to be birds whose mates never part, and in a mandarin duck sleeping alone lies the grief of one who has lost a partner. The poem moves from the plover sequence to the waterfowl sequence, and the next poem, 653, likewise sings of ducks sleeping afloat on the water.
Author
Fujiwara no Masatsune
Source
Shin Kokin Wakashu
Other