Mono no aware
Etymology
A Japanese phrase, literally "the pathos of things": mono ("things") + no (possessive) + aware (a sigh of feeling, an "ah-ness"). The scholar Motoori Norinaga made it central to Japanese aesthetics in the 18th century. English has no single word for it.
noun phrase · /MOH-noh noh ah-WAH-reh/
A gentle, wistful awareness of the impermanence of things, and the tender sadness that beauty is fleeting.
What it names
Why cherry blossoms move people precisely because they fall — appreciation deepened by transience.
Example
Watching the last warm evening of the year fade, he felt a quiet mono no aware.
Related idea
Ephemeral names the brevity; mono no aware names the bittersweet feeling about it. Compare saudade.