"I sincerely hope that only the image of that young me will always be with you."
Satsuki lost her boyfriend, Hitoshi, in a car accident. Unable to face up to his death, she spends her days unable to sleep properly. At some point, Satsuki began to jog at dawn as part of her daily routine, and on a bridge she always passes, she meets a mysterious woman named Urara.
Hitoshi had a younger brother named Hiiragi. Hiiragi had also lost his girlfriend named Yumiko. Hitoshi's car was involved in an accident with Yumiko on board. Hiiragi has been wearing the uniform of the dead Yumiko ever since.
Satsuki has been meeting Hiiragi often to make sure they are both alive. And then, on the banks of the river where Urara led her, she witnessed the "Moonlight Shadow Phenomenon", which is said to be caused by a miraculous coincidence.