People who watched the first season should know that Age of Youth (2) is a  slice-of-life drama about five flatmates living under one roof.  AoY to me was always about the realistic portrayal of friendships. We see how the flatmates stand by and support each other through their individual difficulties. It's really different from most K-dramas which tend to use same-gender relationships as a sort of fan-service. In AoY, all the interactions are natural, not over-exaggerated and not amplified. It's exactly like how I imagined friendships to be (I have no friends, jk). In short, it's an accurate depiction of how friends are like in real life, and as a viewer it's easy to relate to.

There are a couple of cast changes in the second season. In particular, Park  Hye-soo was swapped out for Ji  Woo. I think a lot of people disliked the character. I do agree that she's a lot less likable in this season. Rather than attributing this to the new actress, I feel that the writer has gone slightly wayward in her characterisation of Eun-jae. Or perhaps as viewers we are more partial to the meek Eun-jae than the transformed Eun-jae. I think the scriptwriter probably wanted to show character growth, but the execution was unfortunately not up to par.

Kang Unni is also out of the picture at Belle Epoque, with Choi Ara playing the  new-comer Jo Eun. I liked the introduction of Jo Eun. I thought her character was really interesting, especially her "friendship" with Ye-ji. They also briefly touched on homosexuality, although the topic was quickly brushed over.  After I watched the finale though, I was really confused as to what this "friendship" was to each party. I would really like them to elaborate on it. Anyway, I thought this was a nice touch and they probably could have explored the plotline a little more. I don't really care for her romance with Seo Jang-hoon though. I don't dislike it, but I didn't think it was a highlight. This is just personal and from the comments I've seen, most people quite like this couple.

Ye-eun's loveline is the one I liked most (other than the Song-sung couple that is). I don't know how Onew* would have been, but I feel that Kwon Ho-chang was perfectly cast. And nerds are always endearing. His relationship with Ye-eun is like a reversal of power compared to her previous relationship. In any case, I felt that they were really cute.

Yoon sunbae is the glue that holds the house together. She's seemingly aloof on the outside but she's really taking care of everyone else, and not getting appreciated for it. I don't like the job she was given in this season. I thought that with how they had emphasised so much on her struggle with jobs and internship they'll hand her a job of a higher perceived social status. I'm not saying that working at an entertainment company is bad, but it's certainly no where near the top of my "dream jobs" list. Also, I personally do not follow Kpop and all, so I'm really indifferent to the storyline with the idol group which was cast aside. It's alright, but I think this could be done better.

This season though, the spotlight is on Song Ji-won. I don't think I need to elaborate further on how fantastic her character is. Her story was the focal point this season, and provided some insight on how her personality came to be. I think a lot of people may feel that her storyline didn't get closure, but I thought it was the best way to handle the situation. Because if everything went perfectly, this wouldn't be called Age of Youth. I still like her interactions with Im Sung-min. *SPOILER ALERT* I really do hope for another season just so  we can see them get together. There are hints since the man holding the girl's hand in Ep13 is clearly Im Sung-min, but I would like their relationship to be more explicit and not just implied. *SPOILER ALERT*

In summary, I think AoY is an awesome drama. In the first season my attention waned towards the end but this season I sat through the whole drama, catching up on episodes as they air. I rate the sequel a little higher than its predecessor, though it may just be the freshness playing on my mind.

EDIT: Corrected name of original actor for Kwon Ho-chang.