Owari no Kakera is an original story taking place one month prior to the beginning of the original game. It is told mainly from Akihiko Sanada's perspective beginning with him seeing a mysterious humanoid-shaped Shadow while exploring the Tartarus together with Mitsuru Kirijo. The following day, the story introduces Aya Tokitou (時任亜夜), an upperclassman to the two of them and an original character created for the novel. She is a graduating senior who worked as a manager for the boxing club and harbors a romantic interest in Akihiko which is unrequited due to his generally oblivious nature.