I watched this drama in 2020 on the youtube channel of KBS world. (thanks for that, KBS world!)

The drama is an old one, and you will see this in every detail. Let it be the stage props, the acting, the colors or the way the story is told. From todays perspective, this is a plus IF you like the 00er years and you want to rewind time a bit. But be aware, it looks a bit trashy.
You will see a Korea which is similar to the one you know from todays dramas, but it's definitly a different one.

Besides the age, the drama also have some other strong points:
1. The friendship of Eunbyeol with a fellow (female) student.
This can't be praised more. You don't see many dramas (or even films), where 2 female characters bond with each other from scratch and are just friends, without anything else. And the 2 actresses and the storyboard did a very good job here.
2. The school, gangster-princess, friendship, coming-of-age (and a bit of romance) genres.
You will find these genres more in the J-drama section, but here you get a korean version of it. The main difference is, that the korean way of telling stories is a bit more direct than the japanese way. From a western point of view, you will have a better pacing and the characters actually do what you want them to do, and don't beat around the bushes too much ...
3. 3 stars from today at a young age.
Park Min-Young, Lee Min-Hoo, T.O.P.
This is cool. If you are older, you can check what they did in the 00er years and compare their life with yours. ;) It's refreshing to see Lee Min-Hoo in a silly supporting character roll and Park Min-Youngs - I think first - drama. Both did a good job here.
(when watching on KBS channel: read the YT commets. It's hilarious how many T.O.P. fans watched this drama only for him)
4. The Characters
There are great characters, especially the supporting characters are all very likeable, which helps to generate a lively surrounding for the main cast.
5. The romance part.
There is romance, but it's not the main focus - or at least - the visible romance is not the main focus and not explicitly shown. But you have to figure it out yourself.

Nonetheless, there are also some mediocre points, or points which are "up to you":
1. The Story
The story is honestly not very fancy and also, you have to accept the a somewhat unrealistic reasoning, for why the characters come together and the story takes off.
2. The Music
It's from 2007. You can't compare it directly to 2020, but the main theme is catchy.
3. The Acting
It's from 2007. You can't compare it either. The story pacing is different and the way things were told are different to 2020, but the actors did a good job.

So, should you watch it?
Yes if you like one of this: "Park Min-Young, (T.O.P.), (Lee Min-Ho)", "School, Friendship, Coming of Age, Gangster-Princess", "old dramas".

Otherwise, I would'nt recommend it for you.