Also known as the "Nocturnal Melody."
A blond fighting musician, Demyx uses a sitar as his weapon and controls the Dancer Nobodies. He does not enjoy fighting, but can control and combine water with his sitar for strong attacks such as making identical copies of himself out of water.
He is seen as immature compared to the other members and rather incompetent at completing missions. Initially, he is confused between Sora and Roxas, regarding the former as the latter in their conversations. Demyx first appears in the Underworld, where he plays around with Sora, not taking the young keyblade master seriously. Rather than making a repeat performance, Demyx changes his attitude when he fights Sora again at the Hollow Bastion. Unfortunately for Demyx, Sora defeats him again.
He is voiced by Kenichi Suzumura in the Japanese version of Kingdom Hearts II.