月に叢雲花に風
(Tsuki ni murakumo hana ni kaze; “clouds to the moon; wind to the flower”)

Definition:

Good things are all too vulnerable to disruptions. The moon is covered by clouds; flower petals are scattered by the wind; what you thought would be a thriving democracy is hollowed out and devoured by greed and corruption, hate and fear. Good results depend on a degree of luck, so things don’t always go the way you want or intend.

Breakdown:

This kotowaza comprises two parallel phrases; each uses directional particle に (ni) to apply its second noun to its first. In the first phrase, 叢雲 (murakumo), “gathering clouds” or “a bank of clouds,” is applied to 月 (tsuki), “the moon.” In the second, 風 (kaze) is applied to 花 (hana), “flower.”

In some cases, the two parts may be separated by a comma.

Notes:

Two of the traditional pleasures of nature noted in Japanese culture are the harvest moon, known as 名月 (meigetsu), and a seasonal rotation of flowers (the most famous being cherry blossoms in the spring). Unfortunately, moon-viewings are vulnerable to inclement weather, while cherry blossom is known for shedding its petals quickly.

A related, phrase simply says 花に嵐 (hana ni arashi), “a storm to the flower.” A more general one says 好事魔多し (kouji ma ooshi), “good thing, many demons.”

叢 overlaps in meaning and in its kun reading with 群, so writing 叢雲 as 群雲 is also considered acceptable and does not change the meaning or pronunciation.

Some people apparently use this saying to express when two people’s personalities don’t mesh well, but this is considered an error.

Example sentence:

「せっかく有給休暇取って、弁当のために高い食材も買って、あんだけ頑張って料理したっていうのに、ピクニック当日になって春一番かよ！」　「月に叢雲花に風だね」

(“Sekkaku yuukyuu kyuuka totte, bentou no tame ni takai shokuzai mo katte, andake ganbatte ryouri shitatte iu no ni, pikunikku toujitsu ni natte haru ichiban ka yo!” “Tsuki ni murakumo hana ni kaze da ne.”)

[“Seriously? After I went and took some of my paid leave, and bought expensive ingredients, and worked that hard to make a nice boxed lunch, when the day of the picnic comes we have the first big storm of spring?” “Yeah, things don’t always go the way you want.”]