Part of this movie is based on actual events.

He is doing his best for the defense of the country.

We should do our best to defend our country.

This system is very efficient.

His character affects all the people he is involved with.

It's difficult to overcome this barrier.

This barrier was part of the ancient defense system.

I am planning to go to Seki City in Gifu Prefecture next week.

This ancient artifact is very valuable.

It is very interesting to learn about ancient history.