Reji Sagaya is a young man who was bullied in the past but soon befriended Aoi Misato.
As a child, he was bullied by other kids a lot and he never really stood up for himself. When he first met Aoi, he returned the niceness that Aoi gave him. It was clear that he liked Aoi but he never actually told her. When he grew up, he had an obsession over Aoi and claimed her as his. He now acts more sane and has a more healthy relationship with Aoi.
At a certain point in time, the deaths of people that went to same middle school were occurring. He was the apparent cause of this. He became obsessed with Aoi and brought her to his world. After this incident, he spent most of his time in the hospital but he made a return when the Kodzunu clan was revived. He helped Tatsuma Hiyuu and his friends find Aoi when Tendou Kodzunu took control of the Bodhisattva Eye.
Aoi Misato: As kids, they would take care of his puppy. They were happy around each other. Now grown up, he still cares about Aoi and will help her if he can.