Kids were taking a shower. Before they took it they got stripped down and it showes them naked. (The whole thing shows only once with one angle)

There is the occasional sight of mildly bloody injury. In one scene a man with a head injury brushes against a translucent screen and we see a trail of blood form on it as he stands up.

A Mean teacher beats kids up if they disobeyed him. In the Peking Opera the kids reenacted a war scene. (Meaning that they fight)

Uses of Ass, and Basterds.

The scenes in which a master beats his students may be upsetting to younger viewers.