Given that this manga doesn't have the romance tag the chances of Hina going back to being a boy aren't actually 0 like in other GB mangas where MC becomes infatuated romantically with his friend and so decides to live as a girl so that they can date each other. And it isn't an H manga to say that the continuous sexual activity be it wished for or forced will break his mind and turn him into a sex crazed girl that can't live without a D in her pussy.
But since the point of the story is that hina becomes a girl and his life becomes interesting because of that then nope, hina won't go back to being a guy unless it's at the end of the manga in the last chapter. Kinda like the manga "Oniichan is done for", right now he had the possibility to go back to being a guy but he chose not to, but I won't spoil any more of it.