The heroine has a flawed character and doesn't like many things, the least of which is being owed favors.
The male protagonist is enthusiastic and cheerful, and falls in love with the female protagonist at first sight.
The heroine is average-looking and a top academic.
The male protagonist is good-looking and good at sports.
To put it simply, the male protagonist is a bit silly and sweet (only towards the female protagonist.)
It starts slowly, and in the later stages, the male and female protagonists will be tortured.