How come my high school teachers never dressed up like aliens?

From toplessrobot, This is a commercial for a private school somewhere in Japan. Supposedly it's to help students train for their massive university exam, the test high school students take that pretty much determines the rest of their life. I'm trying to think what kind of Japanese parents would send their kids to a cram school where the teachers apparently dress up like aliens, and all I can think of is "bad ones."