As a child Sakura Mamiya mysteriously disappeared in the woods behind her grandma’s home. She returned whole and healthy, but since then she has had the power to see ghosts. Now a teenager, she just wishes the ghosts would leave her alone! At school, the desk next to Sakura’s has been empty since the start of the school year, then one day her always-absent classmate shows up, and he’s far more than what he seems!

The story of the film begins after the events of the second season, at the graduation ceremony of the third-year students. Knowing that the graduation of the third-year members means the end of μ’s, the nine girls take a walk around the school filled with memories. However, when the students attempt to leave the school gates, a single email is sent to them, and the curtain on a new story for μ’s begins.