Akira Kouno prefers fictional romance to dating in real life and has no plans to change that when Pure Sakurasaka suddenly appears with an impossible claim: she has come from six years in the future, where the two of them are engaged. Akira has no reason to believe her, but Pure’s knowledge and persistence make the future harder to dismiss. Their school life becomes a strange courtship in which one girl remembers a love story the other has not lived yet.