Tomokui Kanata is the previous incarnation of Rou.
Tomokui Kanata was a human with ESP powers and is the previous incarnation of Rou. He died by the hands of Kirimine Aoi, his childhood friend and stalker. On the night of his death he had been out drinking with a female colleague when he saw Aoi alone in the dark, after which she stabbed him with an electrified knife (Nenekaruri) and killed him.
Due to some futuristic surgery procedure, Kanata obtained the ESPers ability Absorption which he used to obtain other abilities and super strength by devouring other entities. He apparently knew martial arts and many combat styles before his death.