expression, ichidan verb
make a blunder; commit a careless mistake
Idiomatic expression meaning to make a foolish or careless mistake, often due to overconfidence or inattention. The literal image is having one's kettle stolen on a moonlit night, implying a lapse in caution.
月夜に釜を抜かれるような失敗をしてしまった。
I made a blunder as foolish as having my kettle stolen on a moonlit night.
The exact origin is uncertain. The expression likely derives from a folk tale or proverb about a thief stealing a kettle under the bright moonlight, symbolizing a careless oversight.