Not so sure this will stay slice-of-life. Or at least, the setting has the option to radically change tack on the drop of a hat...
World has defeated the Demon Lord bent on conquering the world. Check.
After defeat of Demon Lord, the world had an acute case of Peace Breaking Out. Check. Weirder things have happened.
There's a continent behind the Demon Continent that's completely unexplored by Man and Demon. Check.
Hold on... What in name of blazes hangs around on that continent that stopped the Demon Lord from conquering it first, before turning his gentle attention to the Humans...?