The entire first episode qualifies as this. Especially the end. Everyone must have known what was going to happen after Ayumu flew outside the school window, but how every student pulled out cell phones simultaneously and started pictures takes the cake!
It comes back again in the first episode of Of The Dead and this time Mysteltainn breaks and he can't erase their memories now.
And now he created a new fashion because of it.
The ending credits are also very funny. First time seeing them I laughed at how... enthused Eu was about dancing and how Ayumu is slowly drying out in the background. The Fan Disservice scene following the Fanservice shots is also hilarious.