One day, Ji-hwan begins to receive letters from an unidentified person. The letters, containing black-and-white photos of happy children playing, remind Ji-hwan of his old two friends.
Five years earlier, while Ji-hwan is taking pictures with his camera, two girls, Soo-in and Gyung-hee, walk into the frame. Ji-hwan falls in love with Soo-in at first sight. He then musters up enough courage to confess his love to her, but she refuses him very politely. Even so, Ji-hwan doesn't give up and tells them that he wants to be friends the next time they meet. Ever since then, the three of them start a wonderful friendship. They spend time each other always, and consider it the most precious moments of their lives. But they become confused between love and friendship and, finally, Gyung-hee and Soo-in leave him without a trace.
The random letters inspire Ji-hwan to depart anxiously on a long journey to find his old friends, but while looking for Soo-in and Gyung-hee, he confronts a beautiful yet sad secret.