What modern prefecture does the ancient Japanese place name 'Wanokuni' correspond to?

Kunihide Kunitachi is my best friend.

I have been to the Republic of Vietnam.

The system of provinces was a part of the ancient political system in Japan.

My friend is working in the United Arab Emirates.

The German Democratic Republic was once a socialist country.

My dream is to visit the Federal Republic of Germany someday.

The Yemen Arab Republic is a country located in the Middle East.

The Federal Republic of Yugoslavia was once an existing nation.

The Democratic Republic of the Congo is located in the central part of the African continent.