His handwritten letter is very valuable to me.

He wrote the letter by hand.

It's difficult to understand the principles of electromagnetism.

The secret to his success lies in his amazing fortitude.

He has amazing stamina.

He lived in Japan for a while.

I do endurance run training every week.

He made a direct complaint to his boss about his dissatisfaction.

He had the courage to complain directly to his boss.

This dish is a recipe directly taught from the master.