Of all the films I have been able to see on the issues addressed, THIS film is my top 1:

The subject matter is bullying, a bit cliché at first glance, and social pressure / pressure on young people at school. During the whole movie, we can see several times propaganda about studies, like for example "the intelligent go forward and the idiot go backwards" (it was something like that, but the main idea is that). Then we see that the personal problems of the characters are not "important" according to the adult's point of view.
That leaves a lot to be said about the society in which we live in China mainly.
But what stands out the most is the social differentiation between the characters: we have the typical girl who studies a lot, first in her class but who doesn't live in good conditions, her mother is a swindler and lives constantly in hiding, that's why she is rarely seen.
On the other hand we have the boy, a delinquent who doesn't go to class, therefore a person registered as dangerous, who lives in bad conditions, abandoned by his parents but who finds refuge with the girl, a refuge of love and affection that he has not been able to live.

They are two opposing characters who live in different worlds, but who become attached to each other because they have one thing in common: they both seek protection and love. Throughout the story, we follow them in their lives and we become attached to them.
It deserves a 10 because you can't find a film like this, the story is touching and unique. A masterpiece!