Originally, this was a standard helper robot that Seina was issued when he enrolled in the G.P. Academy. However, Kiriko and Erma, not trusting Amane with Seina, added a video camera for surveillance. However, a short circuit, caused by Amane's modifications had altered the personality of the robot. The name "NB" is a reference to Nabeshin, Shinichi Watanabe's character in Excel Saga and Puni Puni Poemi.