Lunatique is the artificial intelligence within Yami's personal spaceship.
Lunatique appears to be a screen with a halloween pumpkin-like face. The exterior of the ship appears in a somewhat gothic-like design. The front window is shaped like a four point star, similar to the one on Yami's clothing. The interior of the ship not only has a control center, but it also has rooms like a bedroom and a shower, suggesting that it is where Yami basically lives.
Lunatique is very loyal to Yami as he always calls her "master" and has also shown some concern for her well being. Yami states that he is like an old friend who would come to her aid when she is on the verge of life and death. However, he can get annoyed when someone is rude to him, most notably Nana, who said he had a bad attitude. In return, he threatened to throw her into space and insulted her flat chest.
Yami mentions that she bought him at a junk shop. Since their acquaintance, the Lunatique serves as her personal spaceship, taking her wherever she wants to go throughout space and would help her escape from life and death situations.
- His name being Lunatique suggests that Yami named him after Tearju Lunatique.