There is an invisible darkness lurking in the distant sky. The sky is just a layer of darkness, blocking this land from the outside world. What is beyond the world? Strong men of countless eras have been looking for this answer...
I don't know which era of ancient books handed down this sentence: "This world has been cursed. A catastrophe will occur every 30,000 years. Only mortal children under the age of ten can survive... And the only safe place is outside the world..."
In order to get rid of the curse, countless strong people practiced hard, just to break through the shady world and find a new home!
