In Fujisawa, Sakuta Azusagawa is in his second year of high school. Blissful days with his girlfriend and upperclassman, Mai Sakurajima, are interrupted by the appearance of his first crush, Shoko Makinohara.

Finally, the day of Mai's high school graduation has arrived. While Sakuta eagerly waits for his girlfriend, an elementary schooler who looks exactly like her appears before him. Suspicious, and for all the wrong reasons... Meanwhile, Sakuta and Kaede's father suddenly calls, saying that their mother wants to see her daughter. She was hospitalized because Kaede's condition had been too much for her to bear, so what could she possibly want now?

When the two girls meet, magic begins. Hazuki Kagimura loves stories, an orthodox girl who is overly imaginative. Because her relationship with her new family does not go well, the environment sends her toward the stories in which she spends her days. One day after school, Hazuki gets lost among the bookcases of the library, leading her to a mysterious school where meets Shizuka Tsuchimikado. It is a magic school where girls (called "mädchen") are selected by the magical texts from which the world's stories are born. Hazuki herself is said to be chosen by the book of Cinderella. In order to become a true magician, Hazuki becomes friends with Shizuka and begins her new life at the school.

Yuzu, a high school gyaru who hasn't experienced her first love yet, transfers to an all-girls school after her mother remarries. She's beyond upset that she can't land a boyfriend at her new school. Then, on her first day, she meets the beautiful black-haired student council president Mei in the worst way possible. What's more, she later finds out that Mei is her new step-sister, and they'll be living under the same roof! And so the love affair between two polar opposite high school girls who find themselves drawn to one another begins!

Three years ago, the world learned that harpies, centaurs, catgirls, and all manners of fabulous creatures are not merely fiction; they are flesh and blood - not to mention scale, feather, horn, and fang. Thanks to the "Cultural Exchange Between Species Act," these once-mythical creatures have assimilated into society, or at least, they're trying. When a hapless human teenager named Kurusu Kimihito is inducted as a "volunteer" into the government exchange program, his world is turned upside down. A snake-like lamia named Miia comes to live with him, and it is Kurusu's job to take care of her and make sure she integrates into his everyday life.