Woowon was an aspiring swimmer who has to work in order to pay off his family's debt (he has to give up so many things in his life and I feel like he doesn't view himself in a very good light even though he's such a sweetheart T__T) while Seo an's trauma from his childhood accumulated (his family is just the worse, belittling his trauma and disorder (except for his little sister who he was and still is really good to)) and an assault from a jealous colleague that resulted in his panic disorder was just so sad. And I love how Woowon was able to help him get through the attacks and even his bracelet was used by Seo an whenever he feels anxious.