Fujita Anju finds herself trapped in an unfamiliar location with several other people.
As their memory loss, as well as the ominous situation, seems to indicate that
something wrong is going on, a weird cubic creature named Dokuroku appears
with the intention to hack into their Prisms, a daily-use microchip implanted in the ear at birth, in order to intrude their memories and retrieve a key element that has been lost in a foggy past.