Katene is an old friend of Hikari Gojō and a brilliant Reyvateil researcher and inventor in Ar tonelico Qoga: Knell of Ar Ciel. He helps Aoto's group revive Tyria and recover the song for the Planet Regeneration Project.
As children, Katene and Mute's parents were researchers in the Archia Think Tank. Although on opposing research teams, their parents constantly discussed their opinions and ideas. Meanwhile, Mute and Katene were left in a special daycare inside the facilities of the Think Tank, where they became playmates.
