Naruto brought Tsunade to the mouth of a valley.
Tsunade looked around, completely baffled. "Why did you bring me here?"
Naruto offered no explanation. He merely grinned, wrapped an arm around her, and leaped into the gorge.
The sudden weightlessness made Tsunade blush. To keep from falling from midair, she could only press herself tightly against Naruto's chest and let him carry her down to the valley floor.
Once they had landed firmly, Naruto began explaining the secret of this place.
"There is a kind of ore in this world called Gelel Stone. It contains an enormous amount of chakra, as well as immense life force. Humans in ancient times once used it to build a civilization beyond their era, but that power was too terrifying. In the end, it drove them to destruction."
He raised a hand and pointed beneath their feet. "And this is where the Gelel Ore Vein is."
Naruto had pondered the origin of the Dragon Vein many times. Where exactly had that chakra, capable of tearing through dimensional barriers, come from?
It was not until he remembered the Gelel Ore Vein from the movie "Mysterious Underground Ruins" that he found the answer.
That ore vein contained enough terrifying power to destroy half a continent. Later, Temujin opened a Space-Time Hole and drew the unsealed Gelel Ore Vein into it.
The immense chakra vanished along with the Space-Time Hole, while the Dragon Vein was born afterward. One appeared while the other disappeared, forming a perfect loop.
So the so-called Dragon Vein was most likely the Gelel Ore Vein that had been exiled to the Dragon Vein World through the Space-Time Hole.
Even a tiny leak of its power could restore vitality to all things and even revive the dead. If the entire ore vein were fully