Natsu is among the last remaining of Soul Guardians, a race of humans witht he ability to transform into feline like people that protect the souls of the dead that have not crossed over. She is a very shy girl, rarely coming out of the forest she lives in to come into contact with others because of the horible childhood of being persecuted for being different. Natsu also plays a flute to summon souls, her only friends. The only thing that sets her appearance apart from other humans, is her long fluffy cat tail.