Heavenly Delusion, Volume 4 by Masakazu Ishiguro

Upon meeting with a cult known as the Liviemen, Kiruko and Maru are tasked to dispose of some man-eaters. Their project would lead them to the people behind the organization known as the Immortal Order. With conflicting ideologies fighting for their services and rare working machinery in the heart of Tokyo, the two must decide whether or not to continue on their quest or to settle down with "civilization".