Reasons for a 5.5 (the lowest I ever rated a drama):
1. Spoiling a good premise
2. Mishandling of well set characters
3. Ruining first season

Reasons this still gets a 5.5:
1. Mark & Kit
2. Kimmon & Copter

P'Pa singlehandedly upsets the delicate balance on which several friendships and relationships were loosely hanging on by and that is pretty much the entire story. 4 eps or so in, the focus that was equally distributed on all 3 couples tilts completely onto Wayu and Thanu, whose plotline is sedative at best and a melodrama at worst. Everyone around them knows how their relationship ought to and ought not to be and why and watching the few romantic scenes they do have between them is just a painful cringe. The situations change and the dialogues are slightly tweaked but it's pretty much the same- Wayu is uncharacteristically confused and muddle headed and Thanu is going to quietly wait until Wayu comes around. We understood that the first time, can we move onto something else now?

Problem is, GenY2 tried its best to present realistic issues that may arise in relationships in a very unrealistic way, not to mention said issues are resolved improperly at best and incompletely at worst. Long distancing, dealing with the exes of past in the present, the difference between the love we give/want to give and what actually the other person needs, the respect that exists in the relationships, meddling third parties...are an interesting set of obstacles one may encounter and thus make for good story elements. But what use are good ingredients when the cooking is a disaster? We are not even talking about Destiny and Fate that were needlessly incorporated into the story in S1. Why have the hide and seek happen and visions of a possible future unfold only to refute the concept of Destiny and its role in love 12 eps later? But then, what about Thanu and Wayu whose story and journey together is an antithesis of the moral GenY2 perpetuates? Furthermore, Sandee, Phai and Padbok are given endings that make one go, "That's it? That's the reason?", making their entire arcs meaningless. Likewise, P'Pa is an unnecessary character if all we are going to get as a reason for him abandoning Wayu is that. 'I don't love you anymore, this is not working for me' is a much better reason.

Wayu and Thanu take up so much of the storytelling that the others don't get their due, Pok and Tong taking the brunt of this damage. Mark-Kit manage to have an exclusive spot for themselves but what little they have is complicated by their (irrational) decision regarding Kit's scholarship. Jack-Ko are necessary (and welcome) comic interludes but Sandee's small crush on Phai is never addressed. It's a pity that everyone except Wayu-Thanu had so much to offer but we see so less of them. Ever since S1, I've had the feeling that Wayu-Thanu were supposed to be the "mature, soft and gentle couple", Mark-Kit, the "cute and playful couple" and Pok-Tong, the "hot, messy, teen couple" and S2 reinforced my belief. But there is a way to show "mature, soft and gentle" and this is not it. The actors are good, except Dun, who needs to improve. Gen Y2 is something that needs fast forwarding even when you're watching it on 1.5x or 2x mode. That says everything about the mess of a drama it is.