classic waka stream

Long ago perhaps
Such a thing may have been said—
Only now I know:
To love someone unseen yet,
One whom I have never met.

Meaning
Perhaps such a thing existed long ago, but only now have I come to know it: that one may fall in love with someone whom one has never even met.
Commentary
111. One Never Yet Seen

There was a certain man. Someone in the household of a high-ranking woman had died.
The poem was composed by the man and sent as if in mourning for the deceased.

It was likely a maid or a relative of the woman who had died. Using this as a pretext, the man sent a poem to a woman he had never met, saying in effect that he had fallen in love with her. It does not seem a very sincere approach.

The poem is included in the Shin Chokusen Wakashū as a poem by an anonymous poet.
Source
Ise Monogatari
Other