Fire's Last Descendant

Sophomore year at O' Sullivan High School is the least of Gabby Johnson's worries. After her worst day at school by far, she returns home to find it nearly in pieces and her parents missing. A giant skeleton, a Gashadokuro, greets her in the mess and says before he decides to kill her, "I will devour your essence slowly, then save the Fire for the master."
Before she is eaten and killed, the Gashadokuro falls into a pile of bones. Two kids about her age come and rescue her and take her to a safe house. Gabby finds that Ankou, the King of Death, has killed only three Elements and that she is the last Element descendant: Fire. And Ankou is out to get all the Elements. He is out to get her.