It's possible to get yourself into a bugged Kitakami state when you encounter Sada/Turo in the crystal pond by pressing the Y button to "go back to a high place", leaving the zone of the event. From that point wild pokemon will not spawn (unless going to the ogre oustin, then they start appearing again but do not trigger wild battles) and you can't access your menu or pokemon, let alone fly away.Going to the union circle will save the game anyway, and next time you load the save file the game will crash, permanently blocking access to the game.
Basically the bug blocks your save file.