The animal kingdom is incredibly diverse, and it is said that there are still species that have not been discovered.

The animal kingdom is known for its diversity and complexity.

He dreams of entering the world of entertainment.

He sometimes forgets his monthly payments.

We exist as a part of the material world.

He is deeply interested in the spiritual world.

He is successful in the business world.

He is highly respected in the education world.

Tatsuhiko is my best friend.

My dream is to enter a national university.