While exploring Kyoto, Naomi Katagaki, a male high school student, encounters a person who introduces themselves as the future version of Naomi, ten years from now. They enlist Naomi's help in changing the course of events that will put their classmate Ruri in danger. In three months, Naomi is set to begin a romantic relationship with Ruri, and they must work together to prevent any harm from befalling her. This collaborative effort is a daring attempt to ensure a better and safer future.