In a certain student dormitory, or rather, a certain student dormitory's bathtub, the girl named Index, watching over the house, was exchanging looks with the stray cat named Sphinx. The calico cat seemed an indoor cat, lacking a cute personality. It did not chase after thrown balls of yarn, nested under tables even after being called and snatched people's food while they ate. The final point was significant to Index, who had a voracious appetite, and to Kamijou Touma, who cooked for her.
It seemed imperative that she train it. Having decided to abandon the loving treatment, she now battled the bubble covered calico cat. As a side note, Index read through Kamijou's elaborate explanation of how to operate the bathroom's automatic hot water supply and had gingerly figured it out.
…But, where did Touma go?
A few questions rested in her mind. The first was from during the conversation. It was not because Kamijou had said that he had wanted to test whether the phone would work but rather when Kamijou had so easily forgiven that she had eaten his pudding.
Speaking of which, it was the same for the shampoo-bubble covered cat whose fur was standing up. To put it simply, Kamijou did not do what he did not want to do. Even if he knew there was no other way, if he truly did not want to do it, he would pursue an alternative.
It was truly odd that Kamijou had not pursued those two things that he disagreed with.
Having decided, Index nodded her head. She exited the bathroom and donned her habit, the Walking Church. At the corridor, before she even opened the door, she realized that even if she wanted to question Kamijou, she had to know where he was. Of course, calling was not an option. In all honesty, Index knew not how to operate the phone and since Kamijou's residence phone had a faxing function, there were so many buttons that Index did not know where to begin.
Would she give up? As Index considered returning to the room, she noticed what appeared to be a tarot card stuck on the wall. It was the runic imprint that the magician Stiyl Magnus utilized.
"…" Index stared at the card with distrust. Something was happening. Kamijou had surely gone alone to deal with something.
Index recalled that a few days ago, she had met the feeling-less teenager. Despair and anxiety caused Index restlessness.
Run. She could only run.
Luckily, with the knowledge of 103,000 grimoires, she understood the workings of Stiyl's magic. The runes required the magician to continuously provide mana to maintain it.
For example, when a soul is lost, a thin string-like something would link the soul and body. Though Index could not use magic, she could trace the mana to prevent from getting lost.
And, like that, Index ran off for the battlefield while neglecting to even lock the door.
She did not know that that action would bring about the worst consequences.