It's a long story
Chinese idiom, Pinyin is Z ú y ī NK ō NGG ǔ, which means a rare person or speech. It comes from Tang Xianzu's reply to Wang Xiangru in Ming Dynasty.
Idiom usage
Used as an object or attribute; used in writing
Analysis of Idioms
Synonym: empty valley foot sound
The origin of Idioms
Tang Xianzu's answer to Wang Xiangru in the Ming Dynasty: "the sound of a foot is empty, but there is Xiangru." Hu xiong'e's poem "can like to ask, with hidden inner son Mu Ji on behalf of Fu to thank" says: "the floating clouds at the bottom of the eye become changeable, the sound of empty valley to the deep."
Idiom explanation
A rare figure or speech.
It's a long story
intelligible even to a senile woman - lǎo yù néng jiě
the grass is always greener on the other side - zhè shān wàng zhe nà shān gāo