Synopsis
A ragtag group of North Korean soldiers led by Commander Lee (Jeong Jae-young) are ambushed. Only Lee, Private Jang (Im Ha-ryong, Arahan, The Big Swindle) and teenager Taeg-ki (Ryoo Deok-hwan) survive. Encountering a strange young girl Yeo-il (Kang Hye-jeong), they find a temporary refuge in her village, called Dongmakgol. Its residents are blissfully unaware that the Korean War has been raging on. The villagers also offer refuge to South Korean soldiers, Lieutenant Pyo (Shin Ha-kyun) and the medic Moon (Seo Jae-gyung) as well as Smith, an American pilot (Steve Taschler). After a tense standoff, resulting in the blowing up of the village's warehouse, the soldiers agree to a reluctant truce, at least until the warehouse and its contents are restored.

Synopsis
After her father dies, So-hee (Kim Hee-sun) writes letters to him believing he has gone to Mars instead of Heaven. Her kind-hearted neighbor Seung-jae (Shin Ha-kyun) does not want to let this innocent girl down and starts writing back to her posing as her father. Years later, this young girl turns into a successful career woman and the helpful young man becomes a postman. Even though these two people may seem to be worlds apart in, Seung-jae still saves his heart for So-hee while So-hee gets lost in her 24-7-business world. One day this young lady who once believed her father had gone to Mars finally finds out who always writes back letters sealed with love. But Seung-jae is now out of sight...