Unlike most stories which pose fictional solutions to the real issue of Japan's declining birth date, this one is not a hentai. I also appreciate that it asked the question: What if you're not cishet in that system?
But while the premise is interesting, it doesn't really matter much to the plot, as it's a pretty generic love polygon.
Where that is concernced, it captures the urgency of young love pretty well and none of it is too forced, contrived or annoying.
All in all, a good watch, I even enjoyed the ending, though they could have commited to it a bit harder.