The story takes place in a fictional world full of monsters and adventurers called Monster Hunters, who, as their name implies, hunt the monsters. The plot revolves around a young Monster Hunter, Shiki, who was taken in as an apprentice to a Monster Hunter named Greylee as a child. A few years after Greylee's death, which was due to a gunpowder incident, he returns to his master's residence, Akamaaya Town, to join the guild there. In that guild, he meets a girl called Ailee and after a series of events, he finds that she is the daughter of his master. From this point onwards, they form a party to find the legendary Myo Galuna, which was Greylee's lifelong ambition.