In the quiet countryside where the original Japanese landscape remains, a sixth-grade girl named Usa lives with her older sister. Her simple goal for the year is to have lots of fun with her friends. On a spring day beneath dancing cherry blossoms, a magical girl named Lily suddenly appears before her. The two quickly become friends, but Lily carries a sad expression and delivers a heartbreaking condition: they can only be together for one year. Usa soon learns that this enchanting friendship comes with an expiration date, and a precious yet sorrowful year of encounters and inevitable partings begins for the two girls. The story follows their developing bond as they navigate the joy of their magical connection alongside the looming awareness that their time is limited. Every day feels magical and full of happiness, creating a poignant contrast with the sadness of knowing it cannot last. The narrative focuses on the theme of cherishing fleeting moments, as Usa and Lily work to fill their single year together with as much wonder and meaning as possible before they must ultimately say goodbye.