Kuroi was wandering, he was on guard duty tonight, but he was kind of wandering around serietei. If anyone were to find him like this, he would probably say, "The normal patrol is predictable, the only way to catch the bad guys is to be unpredictable."
Whether or not he belived it is another matter, but he did however see someone jump up on a roof. Very stealthy, almost as if they didn't want to get caught...
Kuroi had to react, but instead of raising the alarm like he was told to, He attacked.
Kuroi shunpo'ed the distance between him and the roof, silent other than the sound of shunpo. Kuroi then swept at the intruder's legs, moving his hand forward to push her in the back, as kuroi hoped to trip her, and if he did he would start restraining her.