The series is about the mountain-based adventures of a young boy named Sebastian and his Pyrenean mountain dog Belle who live in a small village in France. Sebastian has no friends because he is teased by the other children for not having a mother. But one day, he meets a gentle white dog who has been falsely accused of terrible crimes. He names her Belle and they become the best of friends. To save her from an unjust fate, Sebastian leaves his adoptive family and begins traveling with Belle and his little dog Poochie. They have many adventures as they elude the police and search for Sebastian's long-lost mother.