Their relationship is defined by a slow-burn transition from "partners for happiness" to friends, and finally to lovers.
Serving as the lighter, more classic "first love" subplot, (the "Pretty Boy" of Taeyang High) and Ko Yu-rim represent a more straightforward romantic journey.
While not a traditional romantic storyline, the relationship between Hee-do and her idol-turned-rival is the emotional heartbeat of the series.
Initially defined by coldness and fierce competition, their relationship evolves into a deep, soul-mate-level friendship. They provide each other with a unique understanding that their romantic partners cannot always reach, especially regarding the pressures of professional fencing. 3. The "Pretty Boy" Romance: Moon Ji-woong & Ko Yu-rim
The story is told through the eyes of Hee-do's daughter in 2021 , who discovers her mother's old diaries. This framing reveals that while the romance was transformative, it was a "beautiful, picture-perfect moment" that ultimately served as a catalyst for their growth rather than a lifelong union. 2. The Rivalry and Bond: Na Hee-do & Ko Yu-rim
As they grow older, their career paths—Hee-do as a world-class athlete and Yi-jin as a high-stakes reporter—begin to pull them apart.
They meet when Hee-do is 18 and Yi-jin is 22. Their bond is built on mutual support during their lowest points—Yi-jin finds hope in Hee-do’s relentless spirit, while Hee-do finds a steady anchor in Yi-jin’s maturity.