Just example of Flag generic-ness (is this a word?):
1. The Love-Hate relationship. Well, at least its from Eri's direction, seeing that using the term 'love' for Harima is not appropriate..., yet.
2. Bickering. Bickering. Bickering. How many times do you see this pattern on romantic animes/mangas? Really. Honestly. A million times? More than that, I am sure.
3. Denial of feelings. Again, from Eri's side. "No, I don't like him!" blushes. "No, I hate him" blushes. "No, you're wrong!" blushes. Come on, honestly, can't you say that this pattern is the very definition of generic as hell
4. Both of them are, like, total opposites. Total opposites couple in animes/mangas = genericness.