Shiraishi Kageyuki

Kageyuki Shiraishi is an active duty cop who works in the Crime Lab as a profiler. He's the Director of the Field Ops department set up to solve the X-Day Incidents.

Shiraishi always has a smile on his face, but his words and actions make it impossible for anyone to actually know what he's thinking at any point in time. He's a huge fan of observing cats and humans and is quick to cut ties with anyone he feels bored by.

The protagonist's collar and the emotions she has in relation to it seem to fascinate him.