I just finished the manga. While it was a fun read and probably one of the most entertaining ecchi manga I've read, I'm fine with it ending after three volumes. The whole manga relies a lot on novelty and surprises, which for me was noticeably running out of steam by the end. I'd much rather have it end when it was still pretty fun, than for the idea to be milked to the last drop. Plus, it's quite hard for a new girl to follow up after this. Think about it, the maid served as an intro to the premise, the highschool gal and the store cleric were as different as possible, then the Anubis stuff really shook things up. After the Anubis, it feels like the author was really trying to one-up himself in the craziness and it was kinda overdone.