This was mostly Kwonsuk's story.
A young adult who got robbed of her childhood and potentially happy teenage life when she was basically forced into the ruthless boxing "training" by her own father. Here is where I agree with most other watchers when i say that the redemption arc for the abusive father was at the least uncomfortable to witness. I cannot fathom how within three years someone could change so drastically and this is the one part that doesn't make complete sense to me.
But other than that, I find myself in complete disagreement with other unsatisfied commenters and reviewers.
First of all, I believe that the characters and the choices they made throughout the series were very well written. I could understand all of them because this series portrayed various types of people, all completely different ot one another and all very human. We were shown their weak, embarassing, humble, beautiful, youthful, selfish and loving sides in these 12 episodes. To me they were simply very realistic. A person isn't just good or bad in real life, nor is anyone in the series. Specifically, at the beginning, Taeyoung seemed to think he was pretty self aware, calling himself scum multiple times and seemingly owning up to his fuck-ups. But only after the situation with his friend did he realize how heavy the responsibilities he carries are. Every choice he made after that realization made it a tiny bit easier for him to live with himself, because the guilt won't ever leave him completely, but he knew for sure how to tell right from wrong after experiencing all that pain along with all the beautiful and enlightening moments with Suk.
KwonSuk too had only ever glanced towards the true consequences that her running awat had brought onto her. It was too scary to look at directly. The offer made by Taeyoung at the start of the seires was only accepted by her because she thought it was her only way to stop feeling so scared all the time. After a while she thankfully realised the offer was a one in a lifetime opportunity to right the wrongs of the past. To be brave and do her very best, in order not to regret anything anymore.
(Honestly it was a relief to hear her say multiple times that she hated boxing and putting some blame on her father. If she had blamed herself for the way she turned out I would be really disappointed ngl.)
As for the romance I really don't get other commenters. As we all know, girly had no time or opportunities to ever date and all that when she was young. Which only makes it that much more obvious why she seemed so starstruck by that other idiot. She fell fast and hard, since it was her first time. She simply wanted to enjoy everything that came with that experience and luckily recovered quickly after it was over. But man, to me it OBVIOUS she would come to develop real, strong and uncontrolable feelings for Taeyoung. It was bound to happen. He was the asshole that gave her the solution that she thought she needed to her neverending problem. But he was also the one that fought for her to make sure the situation got turnt completely around and stayed by her side, in any way he could, in order to watch her fulfill her dream and start feeling happy again. He didn't care if she hated him or if something happened to him. He was everything she needed at all those times. (Plus, Sangyeob in this role is so damn charming, I was holding my breath at every scene with him.)
Taeyoung too found something so bright and pure in Kwonsuk's strength and resilience that he was determined to distance himself from her. He didn't want to tarnish her in any way. And only after he had somewhat redeemed himself and stopped the self-punishing, he decided to approach her again. So my point here would be that I could never think the romance was "forced" in this drama. It was slow paced and a bit painful, just as it often is in real life.
Lastly, some people said it undermined the sport. I knew nothing much about boxing before this drama and to me it seemed that it was something sacred basically. From how hard Kwonsuk worked on it even though she wholeheartedly hated it to how other boxers considered her a traitor after her running away causing damage to the sport's prestige, it was clear how seriously everyone took the sport. I'm considering starting classes as we speak.
All in all, between the light, humorous scenes, the romantic first-times, the heartbreaking moments of being forced to face yourself and the violent and hateful sides of that industry, I really enjoyed this drama. (I think I could write so much more about other important points but this is too much already, I apologize)