“cherry blossoms also symbolize clouds due to their nature of blooming en masse, besides being an enduring metaphor for the ephemeral nature of life.
…The transience of the blossoms, the extreme beauty and quick death, has often been associated with mortality.
…Japanese pilots would paint them on the sides of their planes before embarking on a suicide mission, or even take branches of the trees with them on their missions. A cherry blossom painted on the side of the bomber symbolized the intensity and ephemerality of life; in this way, the aesthetic association was altered such that falling cherry petals came to represent the sacrifice of youth in suicide missions to honor the emperor."
1. Lasting for a markedly brief time: “There remain some truths too ephemeral to be captured in the cold pages of a court transcript” (Irving R. Kaufman).
2. Living or lasting only for a day, as certain plants or insects do.
A markedly short-lived thing.