I think his Japanese has improved quite a bit, hasn't it?

I am busy with work during the daytime.

My keys are inside the house.

He received the letter challenging him to a duel and began preparing for the duel.

I love Japan.

Ancient Japan was a place where beautiful nature and culture merged.

I live in Japan.

Gender roles are an important element in defining individual behavior in society.

His role is to fulfill his responsibilities as a leader.

Takasago is an ancient place name in Japan.