海かい底てい撈ろう月げつ

noun

fruitless effort; wasting time on an impossible task

A yojijukugo literally meaning 'scooping up the moon from the bottom of the sea'. Used to describe a completely futile endeavor, akin to 'tilting at windmills'.

• 彼かれの計けい画かくは海かい底てい撈ろう月げつに等ひとしい。

  His plan is like trying to scoop the moon from the sea.