Seijo no Yurikago, Dokujo no Hitsugi  

聖女の揺籃、毒女の柩, เปลนักบุญกับโลงศพของสาวยาพิษ

A pair of siblings without guardians is admitted into a secluded care facility run by a kind nun. However, there's an eerie atmosphere surrounding their stay at this remote location.