-year old Karl Lejon, 'Skorpan' is suffering from tuberculosis and knows that he will die soon. But his older brother Jonathan tries to comfort him by promising that they one day will meet in Nangijala, a magic country beyond the stars. Jonathan dies soon after in a house fire and Skorpan also passes away not long after. They meet in Nangijala, a country divided into the Cherry Blossom Valley and the Briar-Bush Valley. The people in the later are oppressed by the black knight Tengil and his dragon Katla. The two brothers, who now call themselves Jonathan and Karl Lion Heart, decide to help the freedom fighters against the oppression.

Overview from themoviedb.org