A Hero is someone chosen by God to receive a supernatural "gift." A unique existence, only one Hero can exist at a time, with a new one being chosen upon the former's death. This generation's Hero is a ordinary villager girl named Kyrie whose gift is merely being able to boil water. When her family and friends are slaughtered, Kyrie is backed into a corner and learns the true value of that boiling hot power, and how well it could be used to fan the flames of revenge that burned inside of her.

(Source: Square Enix, translated)