I hope there is more to these ideas! In fact, here’s my own:
Basically, everything is up to canon until when Houki first hits Ichika on the head with her bokken when he first saw her out of the shower, by accident. Sadly, or not depending of your pov, Houki’s attack was stronger than she intended, and it lead to Ichika snapping, as his whole personality went a literal 180, which causes him to roughly rape and fuck Houki into submission as not only payback for the epic misunderstanding, but also to get out all the stress of his life prior to that breaking point.
In the end, Houki would be fucked into submission, with all her virginities stolen, and most likely pregnant and ruined for any other man...not that she can find anything wrong with it as she came to love the event, showing that she is indeed a submissive bitch. And cue Ichika taking over the IS Academy, and maybe eventually the world, one girl at the time.