Absolutely top 3 fav dramas of all time!! It is a slice of life drama which I think is why it's not everyones cup of tea since it doesn't have a lot of dramatic plot points and can get slow but I loved it for the fact that it focused on character and relationship development. (Also just a sucker for good slice of life/exes to lovers/established relationship)
Story/characters
I think the strongest point of this drama is that you can relate to the characters so well bc they're very real in the sense that they are flawed in their own way but are living through life and trying to overcome the hurdles life throw at you. I adore how they ended up developing their relationship in a healthy manner and grew to be people that were able t o love each other fully again. I think it was very realistic how sometimes more than love you need to find and love yourself first before being in a relationship. I think the healthiest relationship is when two people are sure of who they are and what they want and know how to be themselves and they find a partner that only enhances those aspects in life and I think this is exactly why woong and yeonsu needed that break. To develop themselves as people and figure out who they are, what they want before being in a relationship again. Getting to know the side characters was also beautiful and the way the side characters were there as support rather than toxic competition was really refreshing, I ended up loving NJ so much in the end although she couldve been easily written as the toxic superstar, she was really the opposite, someone with a lot more layers than you expected. Also super stokes that Jiung ended up having his little happy ending as well;-;

Acting
I love choi wonshik and kim dami so much! their portrayal of these characters was amazing and it felt so real. All the supporting cast was also really well casted, overall acting was superb!

OSTs
Some of the best OST's in a drama I've heard in while!! It's very different vibes from your usual drama Ost ballads but it fits this story so well. I love Christmas tree and I did not know it was sung by V until a good 5 episodes in lol but damn did his voice fit this song and drama so well. The intro song was also lovely and I have most of the OST's in my playlist^^

TLDR
Extrememly well done slice of life drama that focuses on the characters and relationships and portrays them pretty realistically. Very refreshing characters and storyline as well, close to no toxidity/annoying drama tropes/characters. Acting is amazing and OST's are perfect and make this a well rounded, romantic slice of life drama that I'd highly recommend!