Sae-bom discovers a romantic letter written to her mother by Jun (Yūko Nakamura), a Korean-Japanese woman who went to school with Yoon-hee in her youth.
Though the relationship is long in the past and remains a deep secret, Sae-bom recognises her mother's unrelenting loneliness and hopes to comfort her.
Upon graduating high school, Sae-bom insists she and her mother take a celebratory holiday to Japan, knowing Jun resides in the quiet and snowy village of Otaru.
Soon after, Yoon-hee reveals that she knows Sae-bom is aware an "old friend" lives in the village but admits they haven't reconnected.
Saebom's plan works: the two women meet, overwhelmed by emotion, and walk along the canal together.