Despite immersing himself in his book, Itachi never truly became unaware. Why, to become unaware would earn him a scolding, because a shinobi never took for granted their surroundings, even in areas they seemed to trust.

So he heard the footsteps, and chose to glance up, just in time to see the girl sidling up close. Perhaps too close.

"I'm reading." he responds, simply, even though that should've been obvious enough, with the large book in his lap. But he'll give her the benefit of the doubt. His social skills were the ones needing tuning, and he's unaware certain sentences are used to get different answers. One day he'll learn, perhaps.