Responses
I agree. The two are just their own full-fledged story, which simply happen to be intertwined, making it even more interesting.
It's very rare for me to appreciate changes in characters focus (I tend to want to stick to the initial mc) but here the shift worked very well, especially since the first couple had beautiful closure (ie. happy lovey-dovey now)
i'm pretty sure that yoonseol and his bottom are the main couple... yeah, they are. you can't convince me otherwise, the "main couple" doesn't even have screen time. they're side characters.