Seems you are full of nostalgia, Ben. Getting up there in age? ;-P
The song, it seems, was originally Chinese, and the Japanese lyrics written by one of Japan's most famous singer/ songwriters, Masashi Sada (a lot of whose work I really love... his lyrics are masterful and hard to translate because of the subtleties of his vocabulary)
Here's the translation:
When your letter crossed the mountain pass and reached my home
The rice ears were billowing in the south wind.
And your homeland was dyed in amber
("kogane" （黄金) the color of ripe rice and impossible to translate into English... it's "greener" than the gold of ripe wheat or barley)
A lone waterwheel is quietly marking time down by the banks of the river.
A cart is silhouetted within the wild-cherry-colored sunset.
Nothing has changed besides the birth of a calf
But during the days of waiting for you
For fun I learned how to knit.