The Sket-dan get a new assistant homeroom teacher (who wants everyone to call her, Onee-san), but she's a klutz and is upset she can't be a good role model for the students, so the Sket-dan ask Chuu-san to help with some of his strange drugs. Later, Switch goes through some old inventions of his that didn't work out as intended...
Let's try again, bright and cheerful...
Intentémoslo otra vez, 
con mucho sentimiento...
Intentémoslo otra vez, 
con muchas ganas...
Vamos de novo, desta
 vez com animação...