The End Of The World And A Witch's Love summary:

In a world secretly run from the shadows by magic and those who wish to control it, a mysterious academy trains young witches to seek revenge on a world that treats them like tools. Alice, a young magic prodigy, has been taught to live for this goal - while Mari, an almost powerless human, stumbles through life looking for mutual understanding. However, when Mari’s reasons for attending the school become increasingly clear, Alice must cope with revelations of her own!