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...
Onee-san might not look it, 
but she's very passionate!
¡Tal vez no lo parezca, pero 
Oneesan es muy apasionada!
¡Tal vez no lo parezca, pero 
Onee-san es muy apasionada!
Pode não parecer, mas a 
Maninha é muito impulsiva!