You were sitting at the table in your cabinet. Looking through the case of a series of murders that occurred in a month you massaged your temples. You have a strong headache. It was obvious, as you haven't slept for several nights, searching for clues. The job of a detached detective is difficult, but...

"Hello, detective".

Muzan entered the room. He's your work partner, since he decided to take a break from his main duties as a demon lord. And well, he has his own methods of helping you.