This is a form called the tritina. The lines end in a confusing (to me) pattern of 123, 312, and 231 using all the ending words in the last line. aki no sora is the Japanese term for the blue sky of autumn.
Forget-me-not-sky
“The bluebird carries the sky on his back.” Henry David Thoreau
The wild winds came and blew the summer away –
Turning the sky to the heartbreaking blue of forget-me-nots,
and putting a chill into the night air.
Smells of moldering leaves and dried grass perfume the air
and the hummingbirds have all gone away.
Dead are the summer’s forget-me-nots.
I planted years ago the sky hued forget-me-nots
breathing in the cold autumn air
and finally turning with sadness away.
The thin autumn sun warms the air while clouds sail in the forget-me-not sky.

copyright kanzensakura