Being very basic, Bella and Jill are more closely linked to the "Chick" side. Not wearing the cock helmet, getting good grades and that was it.
The teachers, when Derek asks MC which one he prefers, depending on the answer you will have dream scenes with one or the other. Jade will have a few more scenes, and out of dreams, that if I'm not mistaken are not related to being a DIK or Chick, but just going for her.
At first, until the current version, going after all girls is just not an option because sometimes ends up being at the same time during the history of the game, so you end up having to choose one thing or another. Being a DIK or Chick can influence, but that's all. I'm sure this will be worse in the future.