Hanni and Nanni get into a terrible argument about the decorations for their birthday party, which ends with them not speaking to each other for days. The girls in Year 1 desperately try to reconcile the twins, unfortunately in vain. Miss Theobald takes the initiative, invites the two of them to work in the garden and philosophizes about flowers, people and the meaning of the birthday party. This brings Hanni and Nanni to their senses. They make up and write their parents a thank-you note for their birthday and celebrate their birthday together with the class, Miss Lewis and Mademoiselle.