According to his grandfather"s will, the young aristocrat Hugh Anthony Disward inherits an old mansion with a vast library. The will also contains a strange condition that the heir must inevitably take possession of certain "Secret Archives of Dantalian." Arriving to sort out the inheritance, Hugh finds a strange girl named Dalien in the library"s basement. She is the key to the "Dantalian Shelf," a mysterious library that holds forbidden demonic books. Gensho (translated as picture books), forbidden books threaten the harmony of the world, but people cannot resist the allure of taboo. Thanks to the ability to receive help from the "Dantalian Shelf," Hugh and Dalien will now have to deal with problems related to gensho…