仕し事ごとの鬼おに

noun

workaholic; work fiend; devil for work

Describes someone who is extremely dedicated to work, often to an obsessive degree. The word 鬼 (oni, demon) is used metaphorically to emphasize intensity and single-mindedness.

• 彼かれは本ほん当とうに仕し事ごとの鬼おにで、休きゅう日じつもほとんど働はたらいている。

  He's a real workaholic; he works even on most of his days off.

• あの課か長ちょうは仕し事ごとの鬼おにと呼よばれている。

  That section chief is called a work fiend.