Reiko and her husband Tomohiro attend their long-awaited high school reunion, where they reunite with their old friend Yoshihito in a nostalgic atmosphere. The three used to be inseparable and had promised to move to Tokyo together after graduation, but Yoshihito ultimately stayed in their hometown. As they reminisce about the past, they decide to visit their old school the next day and dig up the time capsule they buried years ago. This day marks a new turning point in each of their lives.