Edit: I just re-watched this show and have decided I was a bit too harsh in my first review. Kim Woo Bin's performance is astounding, and I am even more impressed watching it a second time. Suzy has a weaker performance, but I believe it was because she was a newer actor as her more recent performances are much more polished. This time around I found some of the soundtrack pieces to be extremely emotional, and I am not sure why I found them annoying previously.
The show is an out and out melodrama, so there are sub plots that feel over the top, but overall they don't ruin the story. I will say that the main story line of Joon Young's diagnosis and his tumultuous relationship with No Eul is the strongest and most interesting story line for sure, and as a second watch I fast forwarded through a lot of the sub plots.
The parts that were problematic on my first watch and still stuck out to me on the second were the way that both Joon Young and No Eul can be physically abusive to each other at times. I understand they are supposed to be young and frustrated, but it still leaves a bad taste seeing those types of reactions.
Despite all that, the show is strong, and the writing around the main plot is solid. Obviously Kim Woo Bin is the stand out actor here, giving an incredible performance, but I think the side actors did a great job as well. I thought Joon Young's mother was particularly good at playing a character with incredible growth.
Overall, for those who like melodramas and want to see an incredibly emotional performance by Kim Woo Bin, this is a must watch.
For those wondering: I have deleted my original review.
