Initially, Hitomi was offended that Amy grabbed her hand, probably thinking that she'd need help navigating the corridors of the academy.  She was not some helpless invalid!  However, when Amy revealed her strategy of squeezing and tugging her hand to control their advance, Hitomi simply nodded, her way of acquiescing to and acknowledging Amy's cleverness.

The two found the headmaster with little trouble, but, as it turns out, he had also found them.  [i]“I thought I told you two to stay put. Go warn Kaori, Hikaru and Victorique that there is a dangerous presence here. I want you all to stay hidden, understand? This is the final warning.” [/i]

Hitomi furrowed her brow, knowing that [i]this[/i] was the Headmaster speaking to them.  If this 'presence' troubled him enough that he saw the need to warn the other students about it, then Hitomi would obey...although she had this feeling in the back of her mind, that this was a ruse by the headmaster to keep them away from whatever the presence was.  Either way, she was in no position to argue.  Still holding Amy's hand, she gave it a quick squeeze, indicating to her that they should do as he says.