Zettai Meikyuu Grimm: Nanatsu no Kagi to Rakuen no Otome

Henrietta grew up beside the Grimm brothers in their quiet village, surrounded by the fairy tales she loves. One morning she wakes up and everything has changed: the village is empty except for her and Ludwig, the brothers' youngest. With no explanation and nowhere else to start, they set off together to find out what happened to the others.