kou just said that shijima told him how to turn into a supernatural- this is just a theory of mine:
In the anime’s ending towards the end we can see nene falling into the side where hanako is meaning she probably tried becoming a supernatural but then he throws her back to the other side meaning they separate and she stays as a human (/TДT)/
I ALWAYS BALL MY EYES OUT EVERY CHAPTER BECAUSE OF THIS SEVERANCE .°(ಗдಗ。)°.