Koori no Haka Ichiyanagi Nagomu, Sandome no Junan

The accident-prone and chronically unlucky Ichiyanagi Nagomu and his friend Hiyori are invited by Count Arnold of Ruroi to investigate strange occurrences on the secluded island of Cedrei. The late Baron of Cedrei built a mansion to house the spirit of Delia — a young girl who sacrificed herself to seal a demon inside it. Now the demon is restless, and Delia alone can no longer satisfy it. Are the disturbing events caused by the baron's three successors, or by something genuinely supernatural?