A Dusk era has fallen upon this world many times, yet people have managed to survive and reclaim a meager livelihood thus far. Here, in a remote atelier, there was a lone girl making her living by making medicine.

Her name is Ayesha. Several years after her grandfather passed away, her sister went missing and she now lives a solitary life with only her pet cow to call family.

Her sorrowful memories were beginning to fade, little by little, but…

One day, while searching for herbs as usual in the ruins near her atelier, Ayesha saw the figure of her long lost younger sister. Knowing that her sister was still alive somewhere in the world, Ayesha decided to go on a journey to search for her.