"Majo Allied", a country of monsters who live in humans. In order to defeat the strongest monster "Demon King" that reigns there, many heroes appeared and disappeared ephemeral. And now another hero stands up!! But that hero was... a little girl?! The legendary battle for the survival of humanity begins... maybe?!

The spinoff manga follows the character Happy as he is separated from Natsu and finds himself in a world populated by animals.

Keel, the hero of our story, is looking desperately for Siva the so called "best monster fighter" to retrieve something precious that he took away from him, on his search he joins a beginner monster fighter girl, along with her flying pig monster and goes for an adventure to find Siva who for some reason has been missing for two years.