Peter and Anne were not immediately friends when living in the secret annex. In the dramatic version of The Diary of Anne Frank, Peter and Anne frequently tease each other at the start of the play. Sometimes they call each other names. For example, Peter calls Anne Mrs. Quack Quack because she was known at her school for talking a lot. In act 1, scene 3, Anne takes Peter's shoes. He then threatens to get her, and they end up wrestling on the ground over the pair of shoes. This upsets Mrs. Frank because she wants her daughter to stop behaving like a child and the begin acting like a young woman. After, Anne continues to want to spend time with Peter. She asks if she can help him feed his cat, but he rejects her offer. At this point, Anne and Peter are not yet good friends. Nonetheless, Anne wants to be Peter's friend. She explains:

I only want some fun . . . someone to laugh and clown with . . . after you've sat all day and hardly moved, you've got to have some fun. I don't know what's the matter with that boy. (act 1, scene 3)

Later, Peter and Anne learn to enjoy each other's company though they are very different from each other. (For instance, Peter is quieter and likes to spend time by himself; Anne is very social and talkative.) One step towards their friendship is seen when Anne gives Peter and Mouschi (his cat) some nice Hanukkah presents. Later, Anne starts visiting Peter in his room. In act 2, scene 1, Peter and Anne share sodas together. While there, Anne fishes for compliments, telling Peter she isn't beautiful and that her sister is more likable than she is. Their parents are not very happy that they choose to spend so much of their free time together alone in Peter's room. (Anne's mother probably thinks it isn't proper behavior for a young lady to be alone with a young man.) Anne talks about their parents' reactions with Peter:

Aren't they awful? Aren't they impossible? Treating us as if we were still in the nursery. . . When you think what wonderful discussions we've had! . . . Oh, I forgot. I was going to bring you some more pictures.

By this point in the novel, Peter and Anne have become friends. They have long talks and share the few belongings, such as Anne's paintings and Peter's soda, with each other. Peter tells Anne that she has changed. Readers can see signs of growth in both characters. They have learned to respect each other's differences and have started to enjoy each other's company. Peter's companionship with Anne helps her to find happiness in a dark and scary time.