sentences:  Square Enix published a series of light novels based on the title written by Tomoko Kanemaki and illustrated by Shiro Amano.The first volume, "The 14th", was released on July 30, 2009 and the second, "Go to the Sea", on January 28, 2010, and the third and last volume, "Xion-Seven Days", in May 2010.A manga adaptation by Amano was serialized in Square's "Monthly Shōnen Gangan" from August 2009 to August 2012.