Synopsis

The protagonist recounts how she was once a "guest" but became family to rat-like beings, eventually being trapped in a weakened state and forced to supply them with polluted mana to maintain a protective barrier. It is revealed that their world, like others, faced a calamity involving a fissure and the awakening of mana, leading to monstrous creatures. The protagonist also reveals she had saved the rats once, leading them to invite her in and make her their power source, a fact she had previously indulged in but now views as a mistake.