He got tired of doing the same job every day.

We need to confirm his existence or nonexistence.

We always swim in that bay during the summer vacation.

Masao is my best friend.

The difference between his cooking skills and mine is truly like chalk and cheese.

Onium compounds play an important role in chemical reactions.

He is a famous horse owner, owning many racehorses.

Kozo is my best friend.

There is a world of difference between his painting skills and mine.

His wound festered.