Tsuno sometimes seems to talk to herself, but if you listen closely you can hear that she's in fact responding to someone?

Shinobu diagnosed Tsuno with skyzophrenia, often having paranoid crisis and recurrent unreal statements on how the world is dangerous and slayers are manipulator trying to enter her mind, but what can be the scariest, is the self dialogues or even self argument she has.

Her skyzophrenia comes from her mother and is affecting most women in her family.