Yeah, i still wonder how this will be handled.
Chrys - Sumire: At least Chrys seems ready to set something up, so eventually sleeping with Sumire is not impossible, but her power really throws a wrench into the plans. IRRC she is legally forbidden from using her powers, so i'm not sure how MC will be able to risk it. Going "full Naked Gun" could solve it...
The next pair would be Josie - Miranda and while each one of them likes the MC to some extent, i'm not sure how they would react to finding out that MC has already slept with the other. They would also need a bit more screen time (which i fully support).
And last bud not least there is Mrs. Powell. I know that if anything happens it should be at the end of the story and a lot of things will change by then, but i can't imagine how this could be set up.
On a 200% unrelated note, do we know any of the academy girls' superhero names? MC had to pick one fairly early in his career and at least Harper and Riley has been public for quite a while now, but i don't remember anyone mentioning superhero names.