Mukuro's bed is not entirely kept up - he has a general apathy about more than keeping it livable. There's also a tendency for white feathers to end up around the dorm, thanks to the owl that can sometimes be found sleeping on the trunk or otherwise in the room.

Occasionally when Spade is in the room, one of the guards will wander in, pick him up, and walk off with him, making soothing noises and generally treating him like a normal owl; he's given up on arguing and just grumps through it. People are more than welcome to have seen this happen at some point. (Also let me know if you want to harass the owl when Mukuro's not there.)

All of his other belongings are either on him or in the trunk.