If you don't mind sharing, what plotholes?
From what I understand based on the others that I read, uni students have the liberty to choose their classes. Maybe that's why they were together, I ain't sure though. Plus, Taeyang is 23 years old and Hyesung is 20 on the main story, he's not that old might be a junior or a senior.
At 23, He should’ve been graduated. 20 is either sophomore or junior. Of course any age can be in uni, but it’s not shown that Taeyang took any years off. I can get if he’s in a couple of the same classes. I’ve taken higher level classes then came back to lower level ones to have an easier senior year. But he pretty much has the same schedule as Hyesung for two years….
Why is he still in uni, I’d get it if he was doing his masters but he’s in the same classes as Hyesung?? No way he went to military with how weak his body is too so huh, but then again there’s a lot of plot holes for the sake of romance so I guess ….