Story
"Witches lurk among these girls." It was supposed to be Ema's first day of high school. But instead of waking up in her bed, she found herself in a dark prison cell. She found herself suddenly trapped in an island prison, isolated in some unknown, distant sea. In her confusion, an owl informed Ema of her new situation: "You have been identified as a potential witch — a threat to the world. Thus, you will live here as a prisoner for the rest of your life." The life Ema had taken for granted had suddenly collapsed.
Synopsis via AniList (English).
