Mirror Flower, Water Moon (; literally "Mirror Flower, Water Moon"), is a Chinese proverb/phrase (chengyu), also known elsewhere in East Asia (for example, as a Japanese yojijukugo.) The idiom can be rendered in English as "flower in the mirror, moon on the water", suggesting things that can be seen but not touched, being reflected in mirrors or the surface of still water; it is often used as an idiomatic shorthand for "something that is beautiful but unattainable", such as dreams and mirages.[1] A tertiary meaning is "something that seems tangible and simple but has a deeper ephemeral quality."
This name references Japanese: 鏡中的花，水裡的月, which is the shorter form of a Chinese idiom (or chéngyǔ), literally meaning a "flower seen in the mirror, moon on the water's surface".