笹の葉は
This is a famous tanka poem composed in the 7th century by Kakinomoto no Hitomaro and anthologized in the Manyoshu, Japan's oldest collection of poetry (2:133).
Original manyogana:
小竹之葉者
三山毛清尓
乱友
吾者妹思
別来礼婆
Modern Japanese:
笹の葉は
み山もさやに
乱げ友
我は妹思
別れ来ぬれば
sasa no ha wa
miyama mo saya ni
sayagedomo
ware wa imo omou
wakarekinureba
In my own translation, I sought to maintain the tanka's 5-7-5-7-7 form, and I tried to accurately capture the meaning of the terms miyama (lit. "mountain depths") and wakare (lit. "parting" or "farewell"):
Deep in the mountains,
the leaves of the bamboo grass
rustle in the wind.
My thoughts return to the girl
I left behind forever.