Narutaru has definitely taken the place as one of the most fucked up shows I've ever seen. The show is just so strange and brutal. I just saw episode 11 last night, and am hoping to catch 13 tonight. Episode 12 was also one of the few anime episodes I've seen where I felt really really uncomfortable and kind of queasy while watching.
(Crossposted from my anime blog.)
(Also corrected. Ep 12 was the one that messed with my brain)