Responses
It's adapted from a novel and in the novel, they're still in high school. High school settings are different to college settings in many ways. Also, Jaemin is still being watched by his parents strictly because he's still in high school. There is promise from his parents that once he makes it to the top university, he can live alone and have his own life. So I think they couldn't change it to college settings because it would change the story too much.
You do realize highschoolers have sex right?
Why couldn’t they make them collage students