The Sengoku period is a part of Japanese history.

The Heian period was a time when Japanese culture developed greatly.

The Yayoi period is a part of Japanese history.

The ruins from the Kofun Period are important for a deep understanding of Japanese history.

The Ashikaga era is a part of Japanese history.

The Asuka Period is a part of Japanese history, a time when culture and arts greatly developed.

The Muromachi period is a part of Japanese history, a time when many cultural changes occurred.

The Kamakura period was a very important time in Japanese history.

He is always hanging out with bad friends. Truly, birds of a feather flock together.

He is an excellent doctor.