Now in the final chapter of life, Ito can often be found standing under a tall, 500-year-old ginkgo tree. Traumatized by an air raid she experienced 75 years ago, Ito has been unable to recall the events of one fateful day. Ever since then, she cannot help but feel she has forgotten something important. One day, the ginkgo tree triggers a memory: her promise to elope with her boyfriend. As she remembers her 16-year-old self, she heads to the trysting spot for their escape. The long-ago promise they made, risking their lives, now reunites their fractured time and space.