These were secrets among secrets. Even an intelligence expert like Jiraiya still believed the Nine-Tails was a natural disaster.
So how did the Hyuga Clan know?
First, because of their long history. The Hyuga Clan was a great clan that was conservative and regarded continuity as its duty.
The Ninja Academy could hide the history of the past from civilian students, but it could not hide it from a great clan like the Hyuga.
They knew much of the Ninja World's past history.
Second was the Byakugan. Once the Byakugan was activated, none of Leaf Village's secrets could remain hidden.
The Hyuga knew everything, but they simply kept their mouths shut.
"Isn't there a red whirlpool pattern on the backs of our ninja armor? That is the Uzumaki Clan's crest."
"Because the Uzumaki Clan contributed greatly during Leaf Village's founding, the village had their crest engraved on its ninja armor to remember their help."
"So that's how it is!"
Hanabi and Hinata gradually came to understand. Naruto was not some wild child; he had been born to a mother, and he was even descended from nobility.
Hanabi asked doubtfully, "Are Naruto's parents from the Uzumaki Clan?"
Hinata seized on the key point. "Father, you said the First Hokage's wife was the First Nine-Tails Jinchuriki. Wasn't the Nine-Tails a natural disaster?"
Hiashi stopped his two daughters from asking further questions. He put down his chopsticks and said to Hinata and Hanabi, "Enough! Don't ask any more. Knowing too much will not do you any good!"
"Let what happened today rot in your stomachs!"
Hiashi glanced at Natsu Hyuga. Natsu promised, "Lord Hiashi, I did not hear anything."
Hiashi nodded, rose to his feet, and went for a walk.
He somewhat regretted telling Hinata and Hanabi so much. These were Leaf Village's