Some loves leave an indelible mark, a route your heart always remembers, no matter how many detours you take. For Tae-San, a driven team leader with Jang Hyun General Construction, that route leads straight back to his first love.

His mission in Jochiwon is critical: prevent a devastating flood at Heungbok Reservoir. But amidst the looming disaster, fate throws him a curveball – or rather, a familiar face. Lee Su-Yeon. The woman who defined his college years, now standing before him a decade later. Tae-San’s heart hasn't forgotten her, not for a moment. He sees the same thoughtful eyes, the same cautious air, perhaps even a hint of that familiar indifference that once captivated him.

But ten years is a long time. They've both grown, changed, built new lives. Su-Yeon is still Su-Yeon, yet there’s an unspoken distance. For Tae-San, however, the flame never truly died. "You're still the same, Lee Su-Yeon," he thinks, the weight of a decade pressing on his words. He knows he already crossed that invisible line, that boundary of friendship and longing, years ago.

He’s willing to wait, to be patient, to watch her "hesitate and think long and hard." This isn't just about rekindling an old spark; it’s about proving that some love stories are worth fighting for, even against the tide of time and circumstance. Will their paths finally converge on 'National Route No. 1'? Dive into this deeply emotional and human journey through the complexities of first love, second chances, and the quiet beauty of everyday life. This isn't just a romance; it's a testament to enduring connection.

Romance, Slice of Life, First love, Second chance romance, Reunion, Emotional drama, Contemporary, Character development, Manhwa, Adult romance