The theory of spacetime is an important part of physics.

Souroku is my best friend.

Mr. Shimokubo is my best friend.

He is a master of kunai technique, and no one can imitate his skills.

He was promoted to a new position in the company.

He inherited the position of company president from his father.

He is my exclusive chef.

He is attached to that company.

He bought an old painting at the auction.

He is really gluttonous, always eating a lot of food.