Maya Yumeno lives in a world where humans coexist with succubi. Unlike her cheerful succubus friend Chika, who is always ready to "eat" (have sex) with convenient partners anytime, anywhere, Maya dislikes casual sex and only "eats" when she's in heat and without forming any fixed relationships. One day however, a major turning point occurs when she's confessed to by the quiet, introverted classmate Ijima! What she thought would be a purely transactional meal (intercourse) turns out to be a perfect match...?!