Nichijou: Nano Shinonome

A robot girl who was built by Hakase and lives with her and Sakamoto, acting as the matron of the house. Hakase is constantly upgrading her against her will, and Nano worries this will betray the fact that she is a robot, despite the presence of the obvious metal key in her back. Is 1 year old but designed as a 16 year old. Her toes can fire like missiles.