The story starts with our beloved heroine, exhausted from slaying demons, sobbing on the floor.
She is alone in her cold, gray tower. Alone except for the demons she grows so weary of fighting.
She has realized there is no knight coming to save her. No army. No one.
And the demons keep marching steadily forward, relentless in the pain they inflict.
She lays down her sword.
This princess is too weak to save herself anymore.