When he attempts to reign in a bratty student, Gerry is faced with the wrath of his notoriously overprotective and obnoxious mother. Upon realizing that she has fallen into the role of staff "punching bag", Bobbi attempts to transfer the title onto another staff member. Meanwhile, Ricki sells pencils to Robert and drives a hard bargain.
Based on Gerry Dee's real-life experiences as a high school teacher before he switched to comedy full-time, MR. D is a story about a charming, under-qualified teacher trying to fake his way through a teaching job, just like he often fakes his way through life. The premise shines the light on teaching from the teacher's point of view, and as it turns out, teachers don't know everything, especially Mr. D - who struggles to keep one step ahead of his students.