Blue sea star is the most common starfish found in coral reefs. They live in temperate/subtropics regions of Indian Ocean and West Pacific Ocean south of KiiPeninsula. They can grow up to be 20 cm in diameter and are often found in Kagoshima as well.

As the name suggests, most of them are blue, but some of them are yellow or orange. If you look closely, small round bones cover their body, making them very strong.