Who are they?

In a classroom with red walls and wooden desks, a teacher in a black suit stands with her back to the camera, facing students in matching uniforms who are seated and looking forward. The scene cuts to a close-up of a young man in a school uniform, then to two male students in uniform embracing and kissing in a classroom with yellow walls. The sequence ends with a close-up of a blonde student and a female student in uniform, both resting their chins on their hands and looking forward.