あらすじ
The Abyss represents annihilation, instinctively swallowing up all life. But one day, a traitor appeared amongst the Abyss, as the girl Helga woke up confused, only to find out that she was actually the feared being known as the "Midnight Abyss." As she experienced life with humans, she became convinced to use her Abyss powers to defend humanity and to save what was good in the world. But the chaotic forces of the Abyss would not let her go so easily...
あらすじはAniListより（英語）。
