I liked it. :) The story dragged a bit since the main plot revolves most of the time around the prevention of the relationship.
IMHO they found a good story-balance for this specific topic. It could've been easily the prequel for an R-rated movie, but it wasn't. The topic was clearly the character development of all characters. They did well on that part.
To be more specific: They emphasized on the standpoint of the mother to prevent the relationship over the whole storyline and didn't move an inch apart here. In the end, the mother won and the characters under discussion accepted it.
Yes, in the end, they got each other, but that's okay from the story perspective, since they loved each other. It's better this way, than a suicide ending.

For the other parts:
- the filming was OK and typical for a J-Drama. The image quality and colors are bad. It looks like they used a bigger camcorder to film it. From a visual POV this is a no go, but it's IMHO the charm of J-Dramas as well. Since the focus lies on the story, this is fine.
- At first, I disiked the second female lead, but the character did a 180 ° spin and supported the female lead directly and in a friendly way. I liked that.
- The music was quite good, as expected. In contrary to the visuals, J-Dramas emphasize often on the music to get a mood across to the viewer (or listener). It worked here as well.

Would I rewatch it?
No. I usually don't rewatch many shows and only the best or those I really really _really_ liked. Since the story dragged a bit and most of it revolves around the prohibition of the relationship, I can't say it's "fun" to watch. There are also not many scenes included which make me want to see them again. If it was R-rated - yes, then the rewatch value would increase, but that would be a complete different show. Let's be happy to see normal take on this topic, watch it once and let it be.

8.5/10. Slightly better than good average.