Best friends Arlo and Robby are almost identical in what they wear, what they like, and even where they have teeth missing, but when Robby insists on betting on who is going to lose the next tooth their friendship is endangered.
Hoping to get back her lost tooth, Emma writes a series of letters to the Tooth Fairy, but when the wrong teeth keep getting returned the mistakes create complications.
Spencer likes to make the class laugh, but when his remarks hurt Hallie's feelings, Miss Sparks helps the whole class understand the difference between joking and teasing.