Kanan Takakiyo, at first glance, is an ordinary teenage girl who is president of her high school's public morals committee. However, this is all a facade - her true identity is Kanan Zebel, a thousand-year-old demon who is the daughter of Beelzebub, the Great Demon of Gluttony. Eager to consume human souls, she descended to the human world and used hypnotism to convince an ordinary family that she was their firstborn - all so that she could find a student to consume. Her search brought her to Youji Kyougi, her kohai in school who mistakenly believes she wants to go out with him. Unfortunately, there is one caveat to her plan... she has never been in a relationship before.