We finally get some answers to the curse and conclude the story arc in the mansion. As a bonus, we get some of the backstory of Rem and Ram, connecting it back to the Crying Red Demon story from Volume 2.
(Then, it ends with two stupid comic stories, one that is kind of a harem manga knock-off where all the female characters from the mansion take a bath and one about mayonnaise. That's right. Mayonnaise. If you mostly care about the actual story, I advise skipping those.)