A reckless young mouse named Ralph makes friends with a boy in room 215 of the Mountain View Inn and discovers the joys of motorcycling.

Beesus' biggest problem is her 4 year old sister Ramona. Even though Beezus knows sisters are supposed to love each other, with a sister like Ramona, it seems impossible.

Ramona meets lots of interesting people in kindergarten class, like Davy whom she keeps trying to kiss and Susan whose springy curls seem to ask to be pulled.

Ramona's year in third grade is highlighted by the arrival of Howie's rich Uncle Hobart, a change in her after-school situation, a surprise wedding, a death and a new arrival in the family, and her father's getting a job.

When Henry decides to sell bubble gum to all the kids at school to earn money to buy his own bicycle, he gets plenty of trouble, but very little money.

Ramona at 7 1/2 sometimes feels discriminated against by being the youngest in the family.

Ten-year-old Henry tries to show the boss at the newspaper that even though he's not old enough, he can still be a good paperboy.

Maggie resists learning cursive writing in the third grade, until she discovers that knowing how to read and write cursive promises to open up an entirely new world of knowledge for her.

Henry and his friends build a clubhouse, and trouble ensues when they exclude Ramona and Beezus, who try to sneak in.

In his letters to his favorite author, ten-year-old Leigh reveals his problems in coping with his parents' divorce, being the new boy in school, and generally finding his own place in the world.