I feel really torn as how to rate this drama because there were characters that I really adored and then parts of the story that I simply did not enjoy and could have done without. With the drama being 100 episodes (50+ hours!), it makes it even more difficult to give it a fair rating reflective of the overall drama. I have settled on a 7.5, not because it wasn't very enjoyable, but because it simply wasn't perfect - if I were to rewatch this drama, I would only watch for the characters/parts of the story I liked and skip through the rest.

My absolute favorite thing from this entire drama was the relationship between the Yoon doctor brothers - Yoon Gyu Jin and Yoon Jae Suk. These brothers are the epitome of what it is to be a sibling; you love each other, but show it in the oddest ways, bickering like children every chance you can. If you are a sibling, you will definitely associate with these siblings. They cracked me up with their antics, while simultaneously leaving me full and happy with the authenticity of their sibling relationship. The way the writers wrote their relationship dynamics were perfect. I could watch a drama just about them and their lives and be so very happy and entertained.

I also really enjoyed Kang Cho Yeon. Yes, she was very much a bull-in-a-China-shop, but finding her family really helped mellow her out and she became so much more beautiful because you could really tell she became happy. And while I felt her and Song Young Dal recognizing each other as siblings was a bit drawn out in the plot, it was still wonderful once finally established. Seeing everyone together as a huge happy family was really satisfying.

In regards to the romance in this drama (there were a CRAP TON of pairings) I think the couple that carried this drama was the doctor couple, Song Na Hee and Yoon Gyu Jin. They were a couple with serious issues in the beginning even though they still sincerely loved each other (buried deep beneath all the accumulated miscommunication and resentment). Over the 100 episodes, they grew and changed to take care of each other, learning how to love each other again. It was a really well written evolution between the two of them. Their story was what I really kept watching this drama for. I just needed to know how things unfolded for them.

So, the things I didn't like? Hmm. To keep it brief and general:
I felt like some of the romantic pairings were rushed and therefore had no real substance to their attraction. I also felt like some of the romantic pairings were alluded to, but were never confirmed on screen (which, as you can imagine, is super frustrating when you have invested so much time). And then I felt that some of the romantic pairings were simply all wrong and they shouldn't have been put together at all. There were also some characters that I just didn't like, even if the writers tried to "redeem" them. These might seem like small things, but when there are so many romantic pairings, characters, and episodes, these flaws build up into a larger mass of dissatisfaction. Perhaps I'm being too picky, especially for a family drama?

There's so much more I can say about this drama in regards to specific details, but these were the important parts that really stood out to me. The things I loved, mentioned above, were obviously enough to keep me invested in watching all 100 episodes, regardless of character/relationship/plot flaws. I wouldn't necessarily recommend to binge watch Once Again, but I would recommend watching it with a buddy, as I did. Having someone to bounce thoughts off of while casually watching Once Again was the perfect way to enjoy this drama without taking it too terribly seriously. While my 7.5 rating appears mediocre, please recognize that due to the nature of longer family dramas, it is rather inevitable that the story is a bit messier and therefore, not flawless, but enjoyable all the same. If you enjoy family dramas, I would say, give it a chance - there's nothing too heavy or melodramatic in this family drama, which I think makes it a safe family drama selection.