I think is some bug as i have clear all the girls from school and also Hana but still no student council.
If what you say about Hana is true, there's a part of the code that progresses the plot written into her banging scene the first time which activates said code. And if the enthrall points are going up, that means the code for the plot is going up as well. Which explains why its not activating since it's supposed to be set to a specific number.
Put simply, activating Hana's banging event multiple times has made it impossible to progress. So my best recommendation until I can fix this (which shouldn't take too long. I should have it fixed by the end of the day) is simply going back to the first time you banged Hana and then instead of doing it with her again, simply head off to the school in the morning instead.
I'm not sure if that'll work, but it sounds like it might considering what you've told me up to this point.