The manga based off the best-selling The Decagon House Murders novel by Yukito Ayatsuji! The members of a particular university's Mystery Club travel to a ten-sided house on a remote island...which just happens to have been the scene of a gristly, and unsolved, mass murder. Armed with details of the murder and keys to the property, they set out to dig deeper...but can they trust the facts" of the case? And moreover...can they trust each other?"
A group of mystery-loving college students visit Tsunojima Island, the site of an infamous quadruple homicide, and home to architect Seiji Nakamura's unusual Decagon House. Shortly after their arrival, members of the group start turning up murdered, until the fifth day...when the entire Decagon House goes up in flames. <br><br> Meanwhile, on the mainland, Kawaminami and Shimada discover the truth behind the Tsunojima Island murders from a year ago. But when they visit the grave of Chiori Nakamura, a former mystery club member and Seiji's daughter, they find something that turns the case upside down, and Kawaminami receives word that all the club members on the island have died... <br><br> All will be revealed in this final volume!