Once a German, a Frenchman and a Japanese went to work on a mine hill.

Their boss is an American. He said to the German: "You look very strong, so you will be responsible for physical work". He told the Frenchman: "You are an engineer, so you will take the duty of planning for mining". Then he turned to the Japanese: "You look lean and weak, so you will be responsible for supplies."

A week later, they started working.

However, a few days later, the German and the Frenchman found that the Japanese disappeared. But they decided to continue working after searching for the Japanese.
When the German started working, the Japanese jumped out all of a sudden and shouted: "Surprise"!