Ji Hae and Soo Kyung are friends attending the same university and both have a crush on Sang Min who is in their drama club. The more clamorous and outgoing of the two, Soo Kyung, asks Ji Hae to do her a favour; write a love letter to Sang Min. Ji Hae pours out her own feelings for him on paper, but sadly in her friend's name. Touched by the letter, Sang Min is attracted to Soo Kyung, and Ji Hae, feeling uncomfortable and even guilty, tries to avoid him and yet by coincidence or by fate, she keeps running into him. Ji Hae has lived alone with her mom since her childhood when her dad unexpectedly passed away. Her mom is now on a trip abroad, and to wile away her solitude she starts cleaning the attic. There Ji Hae finds a secret box, in which her mom kept the memorabilia of her first love story of some decades past. Summer in 1968 - Joon Ha is visiting his uncle's home in the countryside during his summer vacation. There he meets Joo Hee and falls in love at first sight. One day, the lovely Joo Hee secretly asks Joon Ha to escort her to a haunted house in the village. Happy and excited to be at her service, Joon Ha meets her at their promised spot, but in an unexpected storm, the two lose their boat and barely manage to return home at a very late hour. Joo Hee gets into big trouble for this incident and is sent back to Seoul. Having parted with Joo Hee without a word of farewell, Joon Ha spends the rest of the summer heavy-hearted. With summer vacation being over Joon Ha also returns to Seoul. At school, his classmate Tae Soo asks him to write a love letter to send to a girl. And who would it be but Joo Hee, Joon Ha's dream girl? Unable to confess his own summer love story, Joon Ha reluctantly complies with his friend's request.