In Obereidorf, something is happening. The annual singing competition of the Heidehasen is approaching, and Lamprecht the Seventh, King of the Hares and Rabbits, promises this year's winner his daughter as a bride. She is not thrilled about it, as she doesn't like most of the participants, and besides, she has already fallen for the hare Lodengrün. Fortunately, he turns out to be a great singer. However, among the contestants, there is jealousy and resentment, making it not as easy for Lodengrün as it initially seems.