Synopsis
In the year 2027, Kyoto has been transformed by cutting-edge technology. Among its residents are two high school classmates: Naomi Katagaki, a timid and introverted boy who struggles socially, and Ruri Ichigyou, a girl known for her cold demeanor and sharp tongue. Despite sharing Ruri's passion for reading, Naomi hesitates to talk to her because of her off-putting attitude. One day, while taking a walk, Naomi sees a crimson aurora briefly flash across the sky before disappearing. Soon after, he encounters a three-legged crow and a mysterious figure in a hood, who reveals himself to be Naomi from a decade in the future. The future Naomi explains that he has come to prevent a tragic event that will befall Ruri shortly after she and present-day Naomi begin dating. Though skeptical at first, the current Naomi follows his older self's guidance and gradually grows closer to Ruri, determined to alter her fate. Can he succeed in changing what lies ahead?