The War Against Monsters

It was meant to be a simple, boring day for Kurogane Raijin. He wouldn't have liked to have a boring day, but after Monsters attack Earth, he would rather the day and his entire life just remain boring.

Now, Raijin and his friends have to join the Monster Killers and protect the world as heroes. But, they are not heroes. There are no such thing as heroes in this world. But, the Monster Killers are the world only hope.

Will they be able to defeat the monster king, or will our heroes(?) perish?