The second protagonist. He is a robot who lost his memories. He was rescued by Riko, who found him unconscious in the Abyss. Since then, he has been serving as Riko's pet.
He is very strong. While helping Riko with her job, he lives quietly away from people's sight. A robot like him is exceptionally rare. While being valuable, the orphanage prohibits keeping pets.
Riko adamantly states that he must be a messenger from the the great pit. She believes that regaining his memories will open the path to the bottom of the Abyss.
Who exactly is he? What is at the bottom of the Abyss? Reg is pulled into an adventure by Riko's curiosity and her refusal to listen to anyone.