The first third of Dear Mr. Henshaw consists of a series of letters from Leigh Botts to a children's book author. The letters include a month and date, but the year is purposely omitted so as not to date the book. Leigh writes the first letter while he is in second grade, the second in third grade, the third and fourth in fourth grade, and the fifth and sixth in fifth grade. During the second through fifth grades, Leigh lives with his mother and father in a mobile home outside of Bakersfield, California. From the seventh letter on, Leigh is a sixth grader grappling with a move to Pacific Grove on California's central coast, his parents' divorce, and an anonymous lunch bag thief. He lives in a very small house that is "sort of falling apart" and furnished with items from a thrift shop.

The house sits on...