Mikako, a high-school girl, is called to help fight off an alien invasion, leaving her boyfriend, Noboru, behind. On her journey she uses her cellular phone to send him periodic e-mails expressing her love for him. However, as Mikako feels the passing of weeks and months, Noboru feels the passing of years due to the effects of time dilation. Even then, they realize that they can never truly be apart. <br />