The place where the former angels who fell from heaven and became demons work, the Lord Beelzebub, the Lord of the Demon Realm Pandemonium. As Beelzebub's attendant, the new employee Mulin serves her. Beelzebub is intellectual and dignified... I thought so, but in fact, she likes soft and light girls the most! Even though she is confused about the gap between ideals and reality, Mulin is still shortening the distance between her and Beelzebub every day. Surrounding the two, the clumsy and unique demons. This story is the story before the demons gave a name to "a certain emotion". ... Maybe.