Ms. Postern is a French teacher at Greybridge secondary school. Despite her profession, she knows very little about French culture and has never even been to France. In the series 1 finale, Ms. Postern does get to take her class to France, but due to the school's budget can only take them to a village instead of Paris. When she gets a chance to show off her French skills, her put-on accent makes what she says unintelligible.
Ms. Postern is a ray of sunshine in the otherwise dreary Greybridge. She's always ready to engage in shool activities and treats her colleagues like close friends, despite their flaws.
Mr. Church is the school's chemistry teacher. A foppish, nerdy man, Mr. Church is smitten with Ms. Postern and spends every episode trying to woo her. His attempts usually fail, but he always manages to get back into Ms. Postern's good graces. Mr Church was originally planning on resigning from Greybridge, but when Ms. Postern arrived he changed his mind.
Mr. Gunn is the school's P.E. teacher. A crude, boorish man, Mr. Gunn tries chattig up Ms. Postern any chance he can get. It's abundantly clear that he doesn't really care about Ms. Postern and only wants to sleep with her. Mr. Gunn and Mr. Church frequently wind up fighting each other, sometimes in front of the students, because of their attraction to Ms. Postern.