Jun Ji-hyun
As a young girl, Kim Jeong-min (Jun Ji-hyun) hated writing letters to soldiers because they never write her back once they learn her age. So instead, she pretends to be a teacher, and becomes pen pals with Park Hyun-jun (Park Shin-yang). They plan to meet in person at a train station, but Jeong-min never shows up, and thus their correspondence ends.