I will be honest, I have not watched the first love class. I never saw anything about it that drew me in so going into this, I was prepared to be a little confused plot wise. Luckily, that wasn't really the case and I was able to enjoy the episodes completely. In order of couples, I was really having trouble picking a favorite. I loved all of them. I geuss I'll put Sungmin and Joohyuk at the bottom because their story is my least favourite. The synopsis of their story is completely wrong, which is why I must have been so let down at the start. I am not really into the drunk hookup trope but I thought it would be kinda fun for them. They had chemistry, that NC scene had me in shock, so I felt like it could have worked for them. But instead, they made Joohyuk an ass and had him threaten Sungmin in order to get a date so they could then drunk hookup. Post hookup though, I really liked them. I wish it'd started different but I really liked where it went. My second favourite was Maru and Minwoo, I'm a big sucker for unrequited love. My main, and only, issue with them is Minwoo slut shaming Maru. I get he was upset and Maru had deserved to be lectured but calling him a slut was WAY too far. I wish he'd gotten a little more lecturing but he did apologise and seemed to know that what he'd said was wrong. That aside though, I adore them. I love jealousy (done correctly) and I was living for Maru when Minwoo and Sa Ra were pretending to date. His reactions were everything, I loved it. And now, my favourite couple, Kim An and Lee Hyun. I loved them so much, they had a good plot line and their chemistry was good. My only qualm is the kisses were not good. Especially when you compare to the other two couples, who were doing very well with their kisses. I don't really have any excuses for lip presses anymore, don't join a drama that has kiss scenes if you can't commit to kissing.
Overall, this drama is good and it's worth the watch. You don't have to watch the first season, I didn't, so if the couples interest you than please give this a watch