Bart Simpson; Lisa Simpson; Milhouse van Houten; Martin Prince; Nelson Muntz; Sherri; Terri; Wendell; Ralph Wiggum; Kearney; Dolph; Jimbo Jones; Lewis; Principal Skinner [Seymour Skinner]; Lunchlady Doris; Groundskeeper Willie; Professor Frink; Superintendent Chalmers; Miss Hoover; Rod Flanders; Todd Flanders; General Custo (first appearance; a robot); Gil Gunderson
Groundskeeper Willie is replaced by a state-of-the-art custodial robot.
Miss Hoover; Homer Simpson; Marge Simpson; Bart Simpson; Lisa Simpson; Ralph Wiggum; Janey Powell; Milhouse van Houten; Nelson Muntz; Martin Prince; Steve (first appearance); Edna Krabappel; Umberto (first appearance)
"Lisa takes it upon herself to restore the joy and promise of the teaching profession to Miss Hoover, when the second-grade teacher not only loses her edge but finds herself precipitously close to going over it!" [per solicitation]