Hagoromo and Hamura reached the peak and stood before the Divine Tree. Hamura used his Byakugan and rushed forward towards the tree's roots, targeting one specific one. He tried to open it with a knife, but understood that it wouldn't work well, and he didn't want to hurt what was inside it.
"What's wrong?" Hagoromo asked.
"Elder Brother! Can you deal with this cocoon?"
Hagoromo pointed his palm at the cocoon and used a wind jutsu to cut the cocoon open. But as he did, his heart broke.
"H-Haori!" he said and picked her up, cradling her to his chest. "Haori! Wake up, Haori!"
"Elder Brother... It's no use. She's dead."
"AAAAAHHHHHHH!"
Hagoromo let out a heartbroken scream, feeling anguish unlike anything he had ever experienced in his life. As he felt his heart break, though, his chakra reacted to this state and flooded his brain with yin attributes. When he opened his eyes again, they had changed. Hagoromo had unlocked the Sharingan.
"So this is... the truth behind the Ritual of the Divine Tree."
"This can't continue. We need to do something," Hagoromo said.
"And what, Elder Brother?"
.
They returned to the creek where they had last met Gamamaru and called out to him. The toad didn't let them wait long and appeared a moment later. He looked at the two brothers and saw the change in Hagoromo's eyes. It was enough for him to understand the situation right away.
"It seems like you went beyond that peak..."
"We did."
"Come with me," Gamamaru said and jumped back into the water.
When they resurfaced, they were in an entirely different area.
"Where are we?"
"This is the Land of Toads."
Gamamaru led the two through the land, which seemed so different compared to what they were used to. But what was most strange was the energy they could feel.
"What is this... strange power I feel?" Hagoromo asked.
"Oh?... I'm once again impressed that a human can feel the energy here. And yet, I shouldn't be surprised, you are his son's after all. You have inherited some of his talent, it would seem," Gamamaru said.
"Sons? Are you talking about our Father? Did you know him?" Hamura asked.
"Not personally, sadly. But I do know him. As for the energy you feel, it's called Sage Power or Nature Energy. It flows freely here and is much more abundant, which is why you can feel it so strongly. So, while it is impressive that you felt it, compared to your father, who had never been here... Still, it is impressive."
"What do you do with this power?" Hagoromo asked.
"Well, if you use this power... even someone as small as I can lift these large stone statues," Gamamaru said and demonstrated by lifting one of the statues with ease.
"Wow..."
"Follow me!"
They made it into a large hall, where Gamamaru showed them a large glass marble in the middle.
"This is known as the Memory Stone. Everything that occurs aboveground is recorded in this stone..."
"Everything?"
"Yes. Look at what happened in the past. It will answer some of your questions."
Images started to appear on the Memory Stone, and Gamamaru began to tell the story.
"Long ago, that tree fell from the sky... And, as if in pursuit, your mother Kaguya appeared here. When your mother arrived, she was taken in by the Land of Ancestors. The Land of Ancestors wasn't the biggest land, not by a long shot. But it had developed into the most prosperous and peaceful one. And all of that could be attributed to the young emperor at the time, your Father. Emperor Tenji. There is a lot to talk about when it comes to Emperor Tenji, but if I had to describe him in one word, that would be talented. There was nothing your father couldn't do if he set his mind to it.
From fighting to governing to training to agriculture, economics, politics, pottery, medicine, and even cooking, Tenji could do it all. And he could do it better than anyone else. When your mother arrived, she was like a beacon of something new to the young emperor, and while he was the only one not immediately enchanted by her looks, they shared a very deep bond that developed into love very soon after. Kaguya became pregnant soon after with you two.
However, while it seemed that happiness would be given to them, Kaguya's destiny with humans was to be trifled with by them. They were attacked at night, orchestrated by a coup. The young Emperor experienced ingratitude firsthand, as he had to fight his own soldiers. It was his selfless sacrifice that saved your mother and her servant girl that day."
The two brothers saw the image of Tenji slaughter hundreds of soldiers before he eventually couldn't go on any longer.
"Your father died with a smile on his face. Not regretting anything until the very last moment. This caused Kaguya great anguish, and she became humanity's enemy. She acquired the power of the Divine Tree, and everyone was sacrificed to it. Your father was given a very special place, with his body preserved and looked after by Kaguya. To make sure mankind wouldn't perish, she released some of the humans, erased their memories and put them back. Only your mother knows this truth," Gamamaru explained.
"Where is Mother from? Why does she protect the Divine Tree?" Hagoromo asked.
"I don't know. But your father knew, of that I am certain. Perhaps it is related to the fact that she appeared from far up in the sky. One thing is clear, however. Since the Divine Tree took root, the Nature Energy of this land is being depleted."
"How could this happen?"
"Not just from the land... but from humans too. As long as that Divine Tree exists... this great land will wither, and we will suffer the same fate," Gamamaru finished.
"We must speak with Mother," Hagoromo said.
"But will she even listen to us?" Hamura asked.
"Hagoromo, your mother's power is immense. I doubt you can confront her directly. Even if you are her son, not in the way you are now, anyway."
"Gamamaru, will you teach me how to use Sage Power?" Hagoromo asked.
"Elder Brother! You're not planning to fight Mother, are you?!
"It's just in case..."
"I see..." Gamamaru smiled. "If you, who inherited Kaguya's power and some of your father's talent, acquire Sage Power... hehehe... You could definitely take her on. However..."
"What is it?"
"Teaching you Sage Power is very risky," Gamamaru revealed.
"Why is that?"
"Is there any guarantee that after acquiring Sage Power, you won't become the same as your mother?" Gamamaru asked himself aloud.
"Gamamaru... After coming this far, have you become scared?"
"What do you mean?"
"You're contradicting yourself. Why did you lie in wait for us, then? You planned to pit us against Mother and make us fight from the very start," Hagoromo saw through Gamamaru.
"Heh. You're pretty shrewd for a human, aren't you? Yes, I had a revelation. A dream, more like. Toads rarely, if ever, dream. But that dream was more like a prophecy... I dreamed f you two battling Kaguya," Gamamaru revealed.
"How did it end?" Hamura asked.
"I don't think his dream went that far. If it did, he wouldn't be so nervous."
"Wha--?! How can you see so far into a toad's heart so clearly... Is this another of your father's talents? How unfair."
So, Gamamaru began teaching Hagoromo how to absorb Nature Energy and use it for himself. He told him that chakra was needed to balance the energy, or one would turn to stone. That was, if one wasn't the toads and had evolved with Nature Energy for thousands of years.
"You have acquired Sage Power in no time at all. To think that it only took you this long. But considering--"
"Yes, yes. Considering who my father was. Would you tell me why you always say that?" Hagoromo asked.
"Hehe, sorry about that. You see, your father spent a few years researching the human body and developed various methods to improve it and grow as strong and powerful as possible. Tenji was a monster in that regard, capable of dealing with grown men while he was barely 16 years of age. This was due to the martial arts he developed on one hand, his immense skill in controlling his own body and muscles on the other, and finally to Nature Energy. You see, after focusing on it for a time, your father eventually stumbled on Nature Energy on his own, but understood how dangerous it was. He didn't bother with it, but even with barely touching upon it briefly, he already managed to come up with a special breathing method to take in Nature Energy and nourish his cells slightly. This made him stronger than the strongest human."
"Truly? So Father was truly talented. And all that without chakra..."
"Yes."
"So, how talented am I and Hamura in comparison?" Hagoromo asked a bit excitedly.
"Uhh... well..." Gamamaru sweatdropped.
"What?"
"You're also talented."
"Huuh? What do you mean? That bad?" Hagoromo asked.
"Haha, bad? There will probably never be anyone as talented as you again. But to compare yourself to your father... well, that's just unfair. If your mother had given him chakra, which I think she would have, I can't imagine what he could have accomplished."
.
Hamura was back at home while Hagoromo was learning Sage Power. Suddenly, he felt Kaguya return.
"Mother! You're back so soon..."
"Where is Hagoromo?" she asked.
"Elder Brother is still out patrolling the village," Hamura lied.
"Hamura! Hiding things from me is useless," Kaguya declared and unleashed the power of her Byakugan.
The wind picked up, and the sheer pressure was threatening to overwhelm Hamura. He needed to use his own Byakugan solely to withstand it.
"It's useless... even if you try to repel me with your Byakugan... My Byakugan is far superior to yours."
"Mother!!"
Just before Kaguya was about to overwhelm and knock Hamura out, Hagoromo arrived. Having much more talent than he was supposed to, he had mastered Sage Power sooner and returned in time to see the clash. He flashed next to his brother and helped him stand up.
"Hagoromo..."
"Mother."
"You broke the law and went to that peak, didn't you?" Kaguya said. "Hiding things from me is useless. I can read your thoughts and feelings."
"Then you must know why we're angry with you, Mother," Hagoromo said.
"It seems you were in love with that young girl..."
"Not just her. But everyone from this land, every single one of them... I loved them all, Mother. I also found out what you did in the past. About what happened to father and how it came to this. Why would you hide such a terrible thing?"
"Don't you speak about your father! You don't know anything about him. And you both don't know how dreadful they can be. It's because of what happened that I know an army is necessary."
"They're your soldiers? Mother, just what are you? Where did you come from?" Hagoromo asked.
"I come from a place far, far away in the sky... A place where you two can never go. But someday, they will come to take me back. Love doesn't work on them... They only understand power," Kaguya finally revealed some of her burdens to her sons.
"Still... I saw what happened in the past. Even you must have believed in love?! We are proof of that love!"
"I believed in love. I was saved by it when your father was pierced and impaled by swords and arrows, from weak and greedy humans, for me. When he died to protect us. I believed in it, which is why I shared chakra with you and Hamura. But now, I am to be betrayed by the two for whom your father died, and I shared my power with. My Tenji..."
"Mother, please feel the power of love once more and stop the Ritual of the Divine Tree!" Hagoromo begged.
"I will not!"
"Mother..."
"I protected you and nurtured you all this time. It seems it was all for nought. I shouldn't have listened to him. We will never see eye to eye. So, Hagoromo and Hamura... I am taking back that power and instead use it to bring him back."
And then, the fight between Hagoromo, Hamura and Kaguya began. Kaguya had the power of the Divine Tree, and in order to protect her, it turned into the Ten Tails. The Ten Tails wasn't just the Divine Tree, though; it was also Kaguya herself. It was the manifestation of Kaguya's will, an attempt to reclaim the chakra she had shared with her sons. The intense fighting between Kaguya and the two brothers continued for months. It took a massive toll on the land.
Hagoromo and Hamura both changed and grew more skilled and powerful as the fight went on. This allowed both of them to evolve their eyes. Hagoromo unlocked the Rinnegan and Hamura the Tenseigan.
At long last, however, the decisive moment came to be. Hagoromo and Hamura's powers overcame Kaguya's, and they managed to seal her.