Very good screen writing and intrigue plots and subplots. Characters evolve nicely and their relationships moving.
There are lots of surprises of characters' interactions, conflicts, misunderstanding, or may be reconciliations. Each character has strengths and short comings. They seem to grow following the developments of the story.
It seems that the story/drama also touches on some sensitive topics/or social issues of that era, But the drama does not blame or rationalize those issues. This drama really focuses on the growths of a group of young people of that era. They each has their very different background, and most of them try to set their goals to do better during that era with limited resources.
