I watched it because everyone was saying it was SO good, but I ended up disappointed.
I think the drama is overrated, the story was okay, but there was not much new/ different than any other romance drama.
The ending was fine for me, because I don't think they should have ended together.
She even said at some point that he treated her like a child, and that she felt inferior. Which was indeed true; because he was an adult and she was not, and that type of relationship is not good. He even said that a student should date another student, then why did he ended up dating her? It made me uncomfortable.
He had power over her emotionally, and they were in different stages of their life.
I don't understand why the writer had to make them have that age, the story would have been okay otherwise, it was entertaining and the second lead couple were cute.