Prologue

One September afternoon, I, Aoi Mashiro, was absentmindedly gazing out the window while cleaning the store. There were uniformed middle schoolers outside, presumably on their way home. Today was probably the first day of their new semester. Meanwhile, as a university third-year, I was still on summer break.

“Aoi.”

I flinched in surprise at the sudden voice. Turning around, I saw Kiyotaka “Holmes” Yagashira smiling at me. As usual, he was wearing a black vest over a white shirt, black slacks, and sleeve garters. He was also holding a clipboard since he was in the middle of examining the wares.

“Sorry, I was spacing out,” I said.

“It’s fine. I noticed you were grinning. Did you see something funny outside?”

“Not funny, per se. I was just noticing that the new semester has already start