At night, there's a shot of the boys dormitory which shows a young boy with an older boy, both in bed, sleeping. No nudity as both are wearing pijamas and the sheets are up. They're just sleeping together in the bed.
It's implied (and later confirmed in the dormitory scene at night) that a young boy is gay. One of his teachers has an interest on him, although nothing happens at all.
There's a scene in which a lady inspects the genitals of the boys. No nudity at all, only the boys dropping their trousers. We only see their legs and the woman looking with a lantern at the boys genitals.
The movie is set in a boys' private school. As one might expect, there is a pervasive generalized sexual tension, in part among the boys and in part directed towards girls in general since they are given very little opportunity to interact with girls.
In one boy's dormitory, lewd pictures are posted on the walls.
There is a scene in which a nude man and nude woman (both teenagers) are on the ground snarling and wrestling with each other. The girl's bare breasts are visible as the couple are shown only from the waist up. In the original cinema cut the girl's pubic hair can be seen.
A fully nude woman walks down a hall toward the camera. She then walks into and around an empty bathroom, she is shown from behind, revealing her butt, and then she turns around and her breasts are briefly exposed.
There is a shower scene where the young men are shown nude but only backside views are shown.