Saeyi is happy with Siwan, her sweet, considerate boyfriend. But Ziho, a charming guy from her past, doesn’t bother hiding his interest in her, and she has to admit she feels energized in his presence. Still, she guards her heart. But as her boyfriend becomes increasingly distracted with work and his coworker keeps poking her nose into their relationship, Saeyi fears the worst. Feeling lonely even when they’re together, Saeyi starts to wonder “what if?” as her heart wanders toward Ziho.