
I don't know if they'll include this in the sides stories in the manhwa. But in the novel, Heeseong gave birth to two hybrid wolf-dog puppies. One girl and one boy.
Chi-young is serious about getting impregnated. He's worried about the small size of Heeseong.

Below is the part they start to plan the pregnancy: https://app.yoru(.)world/en/story/378/read/8696
The teachers do realize that the female students will graduate, go to college and/or work, right? Eventually they will interact with other men.
If the mangaka will provide some lame excuse for all this prejudice and hatred towards the other school, they'll get hated.