Keima and Elsie have successfully conquered Ayumi and captured the loose soul. ??But they haven't completed their contract yet...!! Elsie transfers into Keima's class, declares that she's his little sister, and announces that she's going to live in his house as well! All for the sake of rounding up the loose souls in this city... Who holds the next loose spirit? And will Elsie be able to become Keima's little sister??