Hitomi Tsukishiro, a teenage girl born into a family of mages, has lost her sense of colors mysteriously, becoming placid and socially withdrawn. Her grandmother, Kohaku, decides to use time magic to transport Hitomi back in time to meet her 17-year-old self, in hopes to end her granddaughter's suffering. The magic brings Hitomi 60 years back to 2018, and right smack into the room of a boy, where she promptly escapes from the window...