It is a world full of monsters and adventurers who hunt them. They are called Monster Hunters. The plot revolves around a young Monster Hunter, Shiki. When Shiki was a young boy, he was taken as an apprentice to a Monster Hunter named Gurelli, but it was not too long after that Gurelli was killed by a gunpowder accident. After a few years, he comes back to Akamaaya Town (where his master resided) to join the guild there. In that guild, he meets a girl called Irie 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 Miogaruna, which was Gurelli's life-long ambition.

(Source: Wikipedia)