Honestly, I don't really care about Mutsuki. Nor Urie for that matter. The only Q's I care about are Shirazu and Saiko (whatever the hell her name is). I find Shirazu interesting and funny, plus I am thoroughly entertained by the way his speech bubbles are XD Saiko is just funny sometimes, plus apparently shes smart and has a strong kagune. Part of me wouldn't mind Mutsuki dying, only because it would be Urie's fault, and theres the off chance that Kaneki gives him an anatomy lesson as punishment 
Saiko cracks me up every time XD She sleeps all the time, chills on the floor while her partners are getting their asses kicked by Sasaki, and just strolls around on a mission while her coworkers are getting slaughtered to the left and right of her XD
Actually, Saiko also has these characteristic speech bubbles (just not as much as Shirazu):

Edited by trang95, 05 April 2015 - 10:46 PM.