At the same time.
Kusagakure.
"Mui, is your son ready?"
Mui, the lord of Hozuki Castle.
Back when Hyuga Sho's father escaped prison and rescued him... the lord appointed by the Five Great Nations.
Several years had passed, and he had grown even thinner.
Standing before him were four figures wearing animal helmets and black robes.
Kusagakure... the Four Captains.
Unlike the other ninja villages, Kusagakure was not led by a single leader. Instead, the Four Captains governed the village.
"Yes," Mui replied.
"This time, we can open the box..."
"That's right."
The Four Captains took turns speaking.
The box they were talking about.
It was the weapon from the era of the Sage of Six Paths—the Box of Paradise.
According to legend, the ancestors of Kusagakure had once opened this box.
And used it to conquer the world.
"After the efforts of dozens of generations, our hard work is finally about to bear fruit..."
"To open it, we've paid an immeasurable price in sacrifices..."
"Opening the box requires not only an enormous 'quantity' of Chakra, but also the changes in nature of Yin and Yang."
The Box of Paradise had four faces, representing joy, anger, sorrow, and happiness.
The experiments conducted so far.
Even if one face reacted to the Chakra flowing into it, the other faces would cancel out the reaction.
As a result... the box would never open, even after the experimenter died.
"Of all our experiments, we've only managed to open two faces."
"So the other two faces must be lacking Yin and Yang."
The Four Captains spoke.
That was why...
They picked up the photograph on the table.
It was Tsunade.
That's right.
The ones who had hired Tsunade to come to the Land of Grass were none other than the Four Captains.
Of course,