National Route No. 1

Tae-san, a construction team leader, travels to Jochiwon to manage flood risks at the Heungbok Reservoir. There, he has a sudden and emotional reunion with Su-yeon, his college sweetheart. He notices she remains as reserved and careful as he remembers, yet the years apart have shaped them into different people. As old feelings resurface, Su-yeon maintains her composure, urging him to think things over without pressure. She reveals that she has already moved past the boundaries that once kept them apart, leaving the future in his hands.