You know, I could potentially see Natsuki surviving this, if only because this time Tokiko is actually doing something to try and save her, whereas before she has simply stood back and let it happen.
However, the author has already done a fake-out death for her once before and it could be seen as karmatic justice for Natsuki to die, as she's seemingly the only thing that Tokiko actually cares about and she murdered her father because he told her to prioritize her happiness over his own.