Kyuuketsuki Maruguritto to Kuenai Gokinjo, Vampire Marguerite and the Inedible Neighbor, Vampire Marguerite and the Neighbor She Can't Eat, 吸血鬼マルグリットと食えないご近所

Two lonely siblings, Sophie and Benjamin, have been taken in by new foster parents. While exploring their surroundings, they come across the ruins of a mansion from a bygone age. Can the bloodsucking lady of the house spare them some time?