(Hai, Nugu to Sugoin desu.)
"Yes, you won't believe what's under this"

I can honestly say that this episode was full of surprising moments -- from Yuu having to deal with her past, Sera contemplating the moral issues of killing a friend, Dai-sensei blowing stuff up, all the way to Tomonori spawning something pretty scary from inside her. Personally I thought it was a bit too much to cram into one episode. Then again, after I watched the whole episode I felt strangely satisfied at the end.