For this particular drama, my rating doesn't fully reflect my great enjoyment. From the first to the last episode, this drama was adorable. Not silly sweet but refreshingly sweet. No wonder it rushed to the top on the first day of its launch and into the top ten in real-time. Moreover, despite being so young, the main and secondary couples gave such amazing acting performances that I'll follow up their future projects.
It was a beautiful love story, and very well directed (with only minor editing flaws). But it is a simple plot, not intricate or complex twists. Although it had some drama that contributed to the male lead character development, most scenes and dialogues were very simple as expected in a high school setting, and some were shallow (the few cliches included in the plot). So although the love story is a 10/10, the overall drama's simple (but sweet) plot is why I gave it 8.5 (dramas that I think were very good and a rewatch in the future).