Yoon Hee lives with her teenage daughter Sae Bom. On a winter day, Yoon Hee receives a letter from Otaru, Japan. Sae Bom accidentally reads the letter and learns about her mother's first love, which she never spoke about before. Hiding the fact that she knows about Yoon Hee's first love, Sae Bom proposes that they travel to Otaru, Japan together. There, the mother and daughter enjoy their time together. Yoon Hee, believing that she might meet her first love again, feels her heart fluttering.