The main differences in the 'oni chichi manga' and its adaptations lie in the visual presentation and sometimes the pacing. The art style might vary a bit, and certain scenes could be shortened or expanded for better flow in the adaptation. But the core story and characters remain largely the same.
Well, it's possible that the 'oni ga deru' raw manga and its adaptations vary in how they present the story. Maybe there are changes in the order of events or emphasis on certain aspects. However, more research is needed to determine the exact dissimilarities.
The ending of Girlfriend Girlfriend manga is quite complex and bittersweet. The characters go through various challenges and their relationships evolve in unexpected ways.
Renting a girlfriend in manga can happen in different ways. It could be a character responding to an advertisement, or getting involved in a strange pact. The details and mechanics usually depend on the unique world and story that the manga builds.