I'm starting to think this is not a romance. Instead, it's a coming of age that is not shy about teenage sexual tension, a listless adult who doesn't respect conventional boundaries, and an angsty teen finding meaning in a disinteresting world. Their attitude is very art school IMO.
The teacher's meeting was telling. You've got an older teacher warning "the room" but specifically targeting Sakisaka not to be too provocative or get close to the students. I wonder if rumors reached him about the nude painting, or if he's just a fuddy-duddy who's mad that she's a baddy with nontraditional hair. Meanwhile, you've got the himbo homeroom teacher crossing boundaries by hitting on his coworker who is clearly not interested. No comment from the fuddy-duddy about that. The signs point to art sensei getting scandalously fired in the future.