The Mukashi Otoko has become a legend in that village.

Once upon a time, there was a man called the old man of Taketori.

When you listen to the old tales, you can imagine the lives of people in the past.

I learned about the reaction of nitrous acid in chemistry class.

Ayu is my best friend.

He is suffering from a subacute illness.

This species has different characteristics depending on its subgroup.

This airplane flies at subsonic speed.

Hypochlorous acid is a hypo compound of chlorine.

This bird is a subspecies that only inhabits specific regions.