Fourteen years ago, before the tale of Aladdin and Alibaba began, a strange building rose from the depths of the ocean. It was the first of its kind in all of history. Two thousand scientists and ten thousand soldiers entered the dungeon, but none left with their lives. When people started to give up on the Dungeon, the door to the Dungeon opened. Imagine the surprise of everyone when they found out the one who conquered the dungeon was just a mere boy. But that's not where our story starts, no. We're going to go back to before the dungeon was conquered. Going back one year, where we meet our main character. This is the start of the Adventure of Sinbad and Seira.