Yuezheng Longya (乐正龙牙) is a part of the Vocaloid China project. He's described as a forthright person with a sister complex; his sister is Yuezheng Ling. His family owns a large music corporation, in which he hopes to become the president of.
He is formerly known as Yayin (牙音), an originalVocaloid character illustrated by ayaya. His design was a top rank choice during the "Vocaloid China Project".
