"All Yuina wants is to fade into the background. But when this shy high school girl stumbles into a binding contract with an angelic combat android, the two will begin an adventure that will forever change Yuina's life." -- back cover vol. 1.

English language version produced by the staff of NewType USA. Translated by Jack Wiedrick, Hiroaki Fukuda, Gina Koerner, Tomoe Spencer and Al Takai. Japanese language version published by Kadokawa Shoten in 2001.