Dakara Watashi wa Mahou Shoujo wo Yameta

One day, Torika loses contact with her friend Watanabe-chan. Following the last message she finds, she heads to the aquarium, only to find that the aquarium has turned into a labyrinth. While searching for her friend and walking through the labyrinth, she encounters a monster. The monster suddenly appears, and a strangely dressed woman fights it. The woman calls herself a magical girl, and uses fire to repel the monster. She encounters a monster called "Kuiyose" and the "Magical Girl" who fights it. It was the beginning of a new era that would repaint her everyday life.