Hansi, a little canary with a yellow belly, lives happily and contentedly in his cage until the moment one day when a sparrow visits him and tells him all sorts of exciting stories about life outside in the big wide world. Hansi starts to wonder if he is truly happy in his little cage. He wants to know what freedom feels like. And so the two little birds decide to swap homes. A great adventure begins for Hansi, during which he must overcome many challenges, form valuable friendships, and has the fortune to discover the true values of life. In the appendix, the reader will find two small lexicons that entertainingly explain the birds and plants mentioned in the story.