The slow-burn romance of "Twenty Again" was ignited the emergence of the love triangle involving Chan Hyun Suk (Lee Sang Yoon) with soon-to-be divorced Ha No Ra (Choi Ji Woo) and Kim Woo Chul (Choi Won Young).

In the ninth episode of the series, Hyun Suk and Woo Chul were reminded of their past infatuation with No Ra. While Woo Chul became resentful of her as his uneducated wife, Hyun Suk continued to burn a torch for the girl who remained his lone supporter as an aspiring stage producer.

What served as a missed opportunity for Hyun Suk, provided Woo Chul with the chance to seduce the then high-school student.

No Ra reignited their passionate flames with her powerful stage performance during the festival. Her thrilling return to the dance served as a bittersweet reminder for her lost dreams, which were abandoned after her accidental pregnancy.

Hyun Suk attempted to avoid No Ra throughout the episode until she called him out on his juvenile behavior.

His avoidance was likely attributed to the fact that is still a married woman. However, his valiant efforts to remove himself from her were thwarted when No Ra delivered a script to the retreat organized by Woo Chul and his mistress, Kim Yi Jin (Park Hyo Joo).

When No Ra fell ill, after eating quickly to avoid Woo Chul, Hyun Suk came to the rescue with remedies to aid his high-school crush. His sweet attention did not go unnoticed, as Woo Chul confronted him for his actions.

The episode concluded with a face-off between the two professors, as Woo Chul expressed his renewed interest in his wife and Hyun Suk confirmed his desire to pursue No Ra.