While helping out at an anime convention to promote his city, high school student Kakeru Niimi is caught up in a sudden earthquake. During the emergency, he ends up entering a shrine where he sees a peculiar relic shatter. The very next day, his classmate Miyako Kujou, who was cosplaying at the event, worries that she has been cursed as a result of the earthquake, but Niimi brushes her suspicions off. However, Niimi's mind changes when he discovers that various people have gained supernatural powers in the city—and that some have started using them for nefarious purposes. Fortunately, Niimi is not alone: he is joined by Miyako, his sister Sora, and a cold girl named Noa Yuuki, who have all awakened to their own abilities. If the group wants to keep their hometown safe, they must strive to prevent any future incidents while unraveling the mystery behind it all. [Written by MAL Rewrite]

9: Ruler's Crown is an adaptation of the 9-nine- visual novel series, developed and published by Palette.