A Thing Hiding in a Erotic Cult

A Thing Hiding in a Erotic Cult manga summary: Tooru and his sister Yume end up in hospital after a traffic accident leaving their father brain-dead when suddenly Itou Yuuzen appears out of nowhere and takes them under his “religious cult's” protection. Is this the beginning of a new life for the brother and sister or something is hidden behind the facade of this religious cult?