Big Brother (2018) on Netflix

Plot summary

After serving as a United States Marine, Henry Chan comes back to Tak Chi Secondary School, his own alma mater, and the principal hands him class 6B, which the school considers its worst. The students ignore lessons and set traps for him; he confiscates a pack of cigarettes from Jack Li and turns it into a lesson on tar and lungs. Five of them are suspended after a fight with the basketball team, and Henry starts looking into their homes: Gordon Hong, who faces discrimination over his skin color, Gladys Wong, who dreams of racing, and the twins Bruce and Chris Kwan, whose father drinks.