Beverly Cleary's Dear Mr. Henshaw opens with Leigh in lower grades but mostly covers his whole sixth-grade year. Throughout his sixth-grade year, Leigh writes to Mr. Henshaw multiple times on multiple occasions.
The letter Leigh writes to Mr. Henshaw at the start of his sixth-grade year, dated September 20th, informs us that his sixth-grade teacher has assigned the class to write reports on authors. Since Boyd Henshaw is Leigh's favorite author, Leigh decided to write his report on Henshaw and has written to ask him interview questions. The problem is, Leigh should really be doing his research for his report in the library; therefore, Mr. Henshaw does not take his questions seriously and does not respond in time for Leigh to include Mr. Henshaw's answers in his report. When Mr. Henshaw does respond, all he gives Leigh are joke answers, such as that his "real name is Messing A. Round" and he doesn't "have kids because [he] doesn't raise goats." He also asks Leigh a series of his own questions, though. Even though Leigh doesn't want to answer Mr. Henshaw's questions because he is angry about Mr. Henshaw's responses, most of the rest of the letters Leigh writes to Mr. Henshaw throughout his sixth-grade year are answers to the questions.
Through the rest of his letters to Mr. Henshaw that year, we learn a great deal about Leigh, such as the following: Leigh is an average student of average looks and height; his parents have recently divorced, and he moved with his mother from a mobile home outside of Bakersfield, California to a small cottage in Pacific Grove, California, right by the beach; his father is a truck driver; his mother works part-time for a catering company owned by her friend and takes community college courses to become a Licensed Vocational Nurse; he is frequently lonely; and his father often breaks his promises to phone him.