Everyday is a normal day in the small town where Kasuga Arata lives; however, everything changed on the day of the Black Sun, and following it, a magician appears before him. The Black Sun caused the Breakdown Phenomenon which destroyed the town where he lives. Because of this, his normal life was artificially reconstructed by a Grimoire that his childhood friend had left. Just what is the purpose of the magician coming to the town? What will he do with the Grimoire's keepsake?
(Summaries provided by MyAnimeList.net)