Bitter End of the Month

Seok-hee and Hae-yoon are the university students. Seok-hee has loved Hae-yun from the first time they met. When Hae-yoon wants to take a rest before the end of the lecture, Seok-hee suggests to go to the sea together with a photo exhibition. Seok-hee goes to the sea with a letter that she hasn't sent before. Can her letter be delivered to her?