Cosimo Piovasco di Rondò
He is the main protagonist of the story and is titled as a young baron. One day he has a quarrel with his father and as a result runs off to the garden tree. He refuses to come down from the tree for the rest of his life as a result. He goes on to have great adventures with the creatures of the tree. Eventually he dies by hanging himself on a fly away balloon.
Viola D’Ondariva
She is Cosimo's one and only love interest throughout his life. She is from the rival D’Ondariva family so the two were destined to have a sad fate. Though Cosimo goes out of his way to impress her, time and time again she rejects his efforts and goes on to live her own life away from him.
Biagio Piovasco di Rondò
Biagio is Cosimos brother and his best friend. Biagio is shown to be a loyal and kind hearted brother. He and Cosimo would spend days talking whilst the latter lived in the tree and his brought his blankets and other essentials in order to help his survive his new home.
Baron Arminio
The Baron is Cosimo's father and he is a stern traditionalist. He and Cosimo are constantly at odds with each other over the way they live their lives. He tries everything in his power to bring Cosimo down from the tree as he finds his son an embarrassment to his family. Eventually the Baron dies and passes his title on to a reluctant Cosimo. The two never really gain peace with each other.
