I don't know if the school system is integrated between all provinces, but I am surely tell you that in Guangzhou, elementary school lasts from 1-6, middle from 7-9, and high school from 10-12.
Yes, schools in China are hard. You are to take in the rule before taking in the concept behind it. And teachers are a lot stricter, with punishments like standing at the corner or hand-smacking, I think. But my cousin that get a big bruise ob his face for doing bad. It was not from a slap though, the teacher kinda.... can't describe the motion......
But homework is kind of like, pouring rain over you, except it's homework.
And 10th graders have this week-long physical camp where students are out of the house and are in military like uniforms running and exercising. (Mentioned somewhere here.)