Jan Pu♀

Jan Pu is an artificial intelligence owned by Hitoshi Sora as the automatic pilot of his spaceship. (spoiler hidden) When Hitoshi comes to Earth to live in Hazumu's house, he constructs a gynoid modeled after Hazumu's own new female body, so Jan Pu looks about the same age as Hazumu, and their faces bear a striking resemblance. Jan Pu has the unique ability of levitation, and is able to bend light around her so others cannot see her. Other than technically being an artificial being, she generally acts like a human child due to being enthusiastic about meeting new people and possessing little to no social skills for a girl who looks to be the age of seventeen. At home, Hazumu and Jan Pu have been known to take baths together and they sleep together in the same bed every night. Additionally, Jan Pu can eat and finds curry to be delicious. Hazumu's parents take an instant liking to Jan Pu since now they have two girls to dress up and take pictures of. When Jan Pu meets Hazumu's friends for the first time, she is introduced as Hazumu's cousin. Jan Pu loves Hazumu very much, and Hitoshi even had to give her a definition for "love" once she came to Earth in order to describe the emotion she was feeling for Hazumu. She addresses Hazumu as onee-nii-sama (お姉兄さま), and often says the nonsensical word "Pu" during exclamations of emotion.

[From Wikipedia.]