Both lead characters Jin Woo and Ki Sub are very neurodivergent coded with very different coping mechanisms in relation to their respective family members that are directly responsible for raising them. Jin Woo being an isolated regimented perfectionist out of from his childhood habit of earning perfect scores to hopefully get his father's attention to spend time with him. Somewhere along the line he's shifted to thinking that he will never have his father love him more than his father loves his work, but he continues living life the way he always had with everything precisely planned out. Ki Sub never turns anyone down so as to not disappoint them, but he does so anyways when whatever he agreed to inevitably falls apart because he doesn't care like the other person does, which includes relationships with both women and men. He has a mysterious heart condition that his school doctor or nurse sister has been monitoring him for since he was a child and he never wanted to create conflict with her, so just agreeing to everything asked of him. Whatever it is, the show never goes into, but I truly hope his love is truly the miracle medicine needed for his heart to heal.

Ki Sub went through life sublimating all of his desires, but his subconscious seemed to finally fight back with the timeline of spending time with the person he's been unconsciously crushing on since he started college before he immigrates to the U.S. It's absolutely unhinged the way he barges into Jin Woo's home and life. It's interesting how Ki Sub immediately points out Jin Woo likes him and asks him why he won't confess and Jin Woo has witnessed all of Ki Sub's campus confession acceptances and heartbreaking to know where it goes to not want to confess. Ki Sub going through Jin Woo's things is extremely rude too and not right to do and his contract making can be seen as a desperate move he's doing to stay close to Jin Woo before his brain and heart finally connect the dots as to the reason why. His consistent presence is something Jin Woo actually needed, that Ki Sub isn't just going to accept his confession without any meaning. Thanks to modern technology and the culture of filming people without the consent, which also yikes, Ki Sub can see himself outside of his own body how he looks at Jin Woo. He's so used to seeing how people look at him when they like him, he can finally understand what his own feelings are.

Kim Hye Jin is the bi and self aware queen who becomes besties with her perfectionist habit twin Jin Woo who called Ki Sub out on behalf of her friends and crushes and finally finds someone of her own. No notes. Meanwhile Balg Eum is a self conscious wreck to the point that he lashes out physically and emotionally at In Ho he never deserved being abandoned wordlessly in high school and definitely not being treated so violently when he finds Balg Eum again. With the way Balg Eum was punching In Ho, it was like the latter betrayed him or something, but the poor guy was innocent of everything! Balg Eum was just embarrassed that his family is bankrupt while In Ho's seem to be financially stable enough for him to pursue piano and he can afford to buy an expensive watch as a gift in present day too. Though it's not delved into, he could have just saved up for it too, we don't get to know too much about In Ho except that he truly loves Balg Eum unconditionally. I'm glad Balg Eum became self aware at last that it's his own ego problem and he definitely needs time and distance to be a better person, but he really put In Ho through hell. He wasn't even working so much to pay off debt for his family, it was just to save up money to save face for when he one day meets up with In Ho again.

Although Jin Woo and his father finally come to an understanding that the latter threw himself into work as a coping mechanism for the grief of losing his wife and Jin Woo's mom, it was also such a heartbreaking moment when his father offers going home to spend time with Jin Woo and both understand it's too late and not what either needs anymore. It was so civil and such a crushing blow to the heart. Jin Woo is already all grown up, lives on his own, and now has Ki Sub as his companion to enjoy and experience life with. I hope he and his father figure out a way to connect differently eventually. Although we don't get a meeting scene between Jin Woo and Ki Sub's sister, Ki Sub made it pretty clear who is the one that makes his heart beat and calm, so he's pretty much out to his sister and I'll take his word for it that his family is happy for him to make decisions for his own happiness. Jin Woo and Ki Sub's public New Years celebration kiss and no one making any sort of deal about it is so sweet. The little epilogue that they have crossed paths before in high school as they walked in opposite directions during winter time is a lovely little closer too. They always had a magnetic pull towards one another even with a brief glimpse that probably neither even remembers.