In the early 2050s, unknown life forms called “Oracle cells” begin their uncontrolled consumption of all life on Earth. Their ravenous appetite and remarkable adaptability earn them first dread, then awe, and finally the name “aragami”. In the face of an enemy completely immune to conventional weapons, urban civilization collapses, and each day humanity is driven further and further toward extinction. One single ray of hope remains for humanity. Following the development of “God Arcs”—living weapons which incorporate Oracle cells—their wielders are organized into an elite force.

Now there's a mysterious Mask before James Blood, and the man behind it is one that shouldn't exist. What is the mystery surrounding this mask...? So begins an action-packed crime story set in a beautiful city!

Oreki Houtarou is a minimalistic high school boy. One day, he joins the Classic Literature Club at his elder sister's request. There he meets Chitanda Eru, Fukube Satoshi, and Ibara Mayaka. Chitanda is a calm beautiful girl but she turns into an embodiment of curiosity once she says, "I'm curious." Fukube is a smiling boy with a fantastic memory who calls himself a database. Ibara is a short girl and is strict with others and herself. They begin to investigate a case that occurred 45 years ago. Hints of the mystery are buried in an old collection of works of the former members of Classics Club. The collection is titled "Hyouka."

Hyakkaou Private Academy. An institution for the privileged with a very peculiar curriculum. You see, when you're the sons and daughters of the wealthiest of the wealthy, it's not athletic prowess or book smarts that keep you ahead. It's reading your opponent, the art of the deal. What better way to hone those skills than with a rigorous curriculum of gambling? At Hyakkaou Private Academy, the winners live like kings, and the losers are put through the wringer. But when Yumeko Jabami enrolls, she's gonna teach these kids what a high roller really looks like!