His actions are always enigmatic, making it difficult to understand.

A count noun, or 'kasu meishi', represents something that can be counted.

He lost everything.

She is planning a date with her current boyfriend.

My boyfriend gave me a gift.

Everyone was surprised by the news.

He is a well-known author.

He is well-known in that area.

I have been to Mexico.

There is a possibility that unknown lifeforms exist on this planet.