Rebecca lectures her students about the value of education but when the subject switches to dreams and ambitions, she struggles to think of any. Meanwhile, the aliens do a bit of shopping on a shopping network and end up with a brain reading device. They decide to use it on Rebecca but things go awry when Himeko gets in the way and by a fluke accident, Class 1-C has a shared dream that takes place inside Himeko's mind.
When the aliens first acquire the mind reading device, they find a variety of bizarre ways to hide their thoughts from each other.
A fat man and a turtle posing as angels and referring to themselves as Three Musketeers (despite their only being 2 of them) and Four Kings pose as the gatekeepers for Himeko's mind.
Practically everything that happens in Himeko's mind can qualify as shenanigans.