Momoko, an elegant housewife, meticulously maintains her home and attends to her husband, but her devoted care masks an emotional rift between them that blurs the line between love and obsession.

Spring 1991. Takaki and Akari meet in elementary school and continue to exchange letters even after she moves away. They make a final promise to each other to meet again. It is now 2008. They live their respective lives, paths never crossing. Enduring memories and a premonition of that promised day. Even now, their words from that day drift quietly, transcending time and distance. An ephemeral story of a promised reunion with someone precious.