To inherit her grandmother's Dagashi store, art student Kumi Honamanuma relocates to Kyoto where she encounters Harami Mino, K Kusanagi, Mai Haisaka, and a mysterious dog residing in the supposedly vacant shop. Surprisingly, these girls assert they are reincarnated heroes on a mission to thwart the demon king in the modern era. Despite a tranquil existence void of quests, their peaceful routine is disrupted when Ran, a former demon king stuck in the form of a young schoolgirl due to failed reincarnation, appears. The tale kicks off as Ran seeks their help in gathering the scattered fragments of the demon king.