A college student, Jong-pil Jo, gets into an argument with some youths at fast food restaurant in Itaewon, South Korea. The boy is later found stabbed to death in the restroom of the restaurant. Two Korean-Americans, Pearson and Alex, are known to have gone into the bathroom after Jong-pil Jo and become prime suspects. The prosecution must now determine which of the two committed the crime.
The countless killifish in the neighborhood brooks that swam so fast creating rainbow glitters, the colorful dragonflies which painted the autumn sky with their black and red tails… the old man who lived down the street and gave the smile of the day as he hears the little tunes of the children… old granny who always put a lollipop in our tiny hands after every Sunday supper… where did they all go? To Mars...perhaps? - A mysterious love story delivers a very special reminiscence to all.
Little Seung-jae stays up all night and writes letters to So-hee, pretending to be her father in Mars. Leaving Seung-jae’s innocent heart behind, So-hee leaves for a big city. Both grown up to be adults, Seung-jae is a postman who writes letters to So-hee’s grandma - the letters that never came from So-hee. So-hee’s heart hardens after hardships in life and she comes back to her hometown and Seung-jae’s heart swells up again at seeing her again.