みずをえたうお
someone who is in their element; fish that has found water
Expression, Noun
テニスのことになると彼女かのじょは水みずを得えた魚うおのようだ。
She is in her element when it comes to tennis.
畑仕事はたしごとをしているとき彼かれはまるで水みずを得えた魚うおのようだ。
He's in his element when working on the farm.