JBridge said: Looks like a Nisemonogatari reference to me.
Exactly what I was thinking... though they should have added a little more...
Hey Misaka. I'm going to brush your teeth so open your mouth.Brushing Mikoto's teethHuh?W-Why?That was really painful and painful, so...I don't want you to experience that pain, you know?Therefore, open your mouth!Do you want me to do it by force, or will you open your mouth obediently!?*He only wants to teach her the importance of brushing teeth.*startle*Ahh...All right. Good girl, good girl.*brush brush*My mouth... is getting tired...Hey! Open your mouth properly!*Thinks that she was scolded.Yessir...Actually, Mr. Kamijo had a rotten tooth, and was drilled by the dentist...I've personally learnt the importance of brushing teeth, that's the story here.Long-winded talkI do brush my teeth properly, and I don't have a rotten tooth eith-...I only wanted to brush her teeth, yet...Misaka...*He only wants to brush properly, that's all.But having my teeth brushed... It feels good, I think.This is nice... somewhat.*flutter**brush brush*