A mouse named Wemberly, who worries about everything, finds that she has a whole list of things to worry about when she faces the first day of nursery school.

Nancy is about to lose her first tooth, but if she can prevent it from falling out until she arrives at school she will get a special necklace from the nurse.

When a child has a "bad speech day" at school, his father gives him a new perspective on his stuttering.

Third-grader Arthur is amazed when he is chosen to be in the school spellathon.

When Ms. Albert teaches a lesson on kindness, Chloe realizes that she and her friends have been wrong in making fun of new student Maya's shabby clothes and refusing to play with her.

Nancy, who likes to use fancy words, decides to make an homage to her little sister's pet goldfish as her project for the 100th Day of School.

"The crayons are getting ready to go back to school, and each crayon has a subject they're looking forward to the most. They're also ready to meet new friends...and let loose during their very favorite time of day: art class"--

Splat the cat's bicycle bumps and jumps over the bumpy track on his way to school, until . . . crack! Splat takes a tumble off of his bike and finds himself nose to beak with a duck. When the duck does not make a sound, Splat packs the duck in his backpack along with his school supplies to his teacher, Mrs. Wimpydimple, who will know what to do, and heads off to Cat School.

Preparing for picture day at school by choosing just the right outfit, Nancy wonders how she should style her hair and considers pigtails, a bun, and long ringlets before formulating a plan that has her reaching for the scissors.

The students of Diffendoofer School celebrate their unusual teachers and curriculum, including Miss Fribble who teaches laughing, Miss Bonkers who teaches frogs to dance, and Mr. Katz who builds robotic rats.