"Thanks for coming all the way out here."
"Oh, don't mention it. We wanted a relaxing trip too."
After four years together, Yeon-hee and Seon-rin are happily engaged and planning to get married next spring. For a vacation, they visit the quiet town of Musan to spend time with Yeon-hee's close friend, Yoon-ji, and her husband.
Surrounded by Musan's peaceful scenery, the two couples enjoy what begins as an ordinary getaway. But before long, they find themselves sharing a series of private moments that slowly change the relationship between all four of them.