See how often they participate in the script: HERE.
Character Story: Jovani is a man known for his greed. He sold his soul for wealth, but quickly regrets that when he becomes frozen in gold. Luckily he meets Link who agrees to search all of Hyrule and return his soul to him piece by piece.
Race Story: Humans typically live peacefully with other races throughout all of Hyrule. The more specific Hylian race is a subcategory of humans. They can be differentiated by their ears -- Humans have rounded ears and Hylians have pointed ears.