A lonely young boy, overshadowed by his older brother, picked on by other boys at school and ignored by his businessman father, finds strength and companionship from a stately old oak tree. When his father, a real-estate developer, plans to demolish the old tree in order to make way for a factory, the boy decides to stand up for his friend and stand up to his father.

On the eve of Yugoslav war in 1991, English ecologist Henry comes to the city of Osijek in order to save the world's oldest oak. After many dangerous and funny adventures, they finally arrive to nearby village where the oak is located.

Milenu is based on very popular Eritrean story about a girl whose parents wanted to marry her to her own brother. Being in love with another young man, she refuses her parents' decision and flees the village to take refuge up in an oak tree.