The gates of Konoha appeared through the morning mist, familiar and unchanged. Seiji walked through them with the dawn at his back, his white mask packed away, his pale eyes fixed on the path toward the Senju compound. The mission to Roran was complete. Mukade was dead. The Dragon Vein was sealed. But Seiji carried something new within him—a knowledge that burned behind his Tenseigan, a path that stretched into unknown territory.
Sage Mode. The ancient art of blending natural energy with one's own chakra. The Dragon Vein had shown him the foundation, but the knowledge was raw, unrefined. He needed time. He needed solitude. He needed to learn to balance the primal power of the planet with the cold precision of his own being.
He found Mikoto in the garden, her hands cupped around a steaming bowl of tea. The koi pond rippled in the morning light, its fish clustered—as always—at the far side. She looked up as he entered, her dark eyes sweeping over him, checking for new wounds. Finding none, she smiled.
"You're back. The mission?"
"Complete. Mukade is dead. The Dragon Vein is sealed." He sat beside her on the wooden bench, accepting the tea she pressed into his hands. He did not enjoy tea. He drank it because she made it. "But I learned something. Something that requires further pursuit."
She studied his face, her expression shifting from relief to curiosity. "What kind of something?"
"An ancient art. Sage Mode. The ability to draw natural energy from the world itself and blend it with chakra. The Dragon Vein showed me the foundation—it's a conduit to the planet's life force. But mastery requires training. Solitude. Time." He paused. "I need to go away, Mikoto. For months. Perhaps longer."
Her hands tightened around her tea bowl. "How long?"
"I don't know. A year. Two. Sage Mode is not like ordinary jutsu. The natural energy must be balanced perfectly with my own chakra. If I fail, I will turn to stone. If I succeed, I will gain power beyond anything I have achieved before."
"Then let me come with you. I can help. I can—"
"No." His voice was gentle but absolute. "Natural energy is dangerous. If I lose control, I could destroy everything around me. I will not risk you. I will not risk Akane. This is something I must do alone."
Mikoto was silent for a long moment. Her dark eyes glistened, but her voice was steady. "You're asking me to let you go. To not know if you're alive or dead. To wait, not for days or weeks, but for years."
"I am asking you to trust me. To believe that I will come back to you." He touched her face, his cold fingers gentle against her warm skin. "I have faced Kage and walked away. I have stopped the strongest spear with my own body. I will master this. And I will return."
She stared at him. Then, slowly, she nodded. "You'll write to me. Not every day. But sometimes. I need to know you're still alive."
"I will write. I promise."
She leaned her head on his shoulder. "Then go. Learn your Sage Mode. Become whatever you need to become. I'll be here when you return. I'll have tea ready."
"I don't even like tea."
"You drink it because I make it. That's love." Her voice cracked, just slightly. "Come back to me, Seiji. Whatever it takes. However long it is. Come back."
He held her in the morning light, the koi pond rippling beside them, and made a silent vow. He would return. He would master the ancient art. He would become more than a weapon. And he would come home to the woman who loved him.
That was enough.
He spent three days preparing. Gathering supplies. Studying the fragments of knowledge the Dragon Vein had implanted in his mind. The natural energy of the world was not something that could be learned from scrolls or teachers. Jiraiya, the only shinobi Seiji knew who had any experience with Sage Mode, was himself still learning the art from the toads of Mount Myoboku. He could offer no guidance beyond what he had already discovered: natural energy was perilous, balance was everything, and the cost of failure was petrification.
So Seiji would learn alone. He would find a place where the planet's energy flowed strongly—a place like the Dragon Vein, or the ancient forests where the trees themselves pulsed with life. He would meditate. He would experiment. He would risk the stone death. And he would succeed, because failure was not an option.
The night before his departure, he wrote a letter to Mikoto. It was brief, because words were not his medium. But he needed her to understand.
Mikoto,
By the time you read this, I will be gone. I don't know where I'm going yet—somewhere remote, where the natural energy is strong. The Dragon Vein gave me the knowledge, but I must find the path alone.
I will write when I can. I will return when I am ready. I will think of you every day—not in the way poets describe, but in the way I calculate my survival. You are my anchor. My reason for becoming more than a weapon. I will not fail you.
Wait for me. I'll have tea with you when I return. I still won't enjoy it. But I'll drink it because you made it.
That is love. You told me that. I am learning to believe it.
Seiji
He left the letter on her bedside table, kissed her forehead as she slept, and walked out of the Senju compound into the predawn darkness. Akane was waiting at the gate, her massive silver form a silhouette against the stars.
You are leaving, she said. It was not a question.
"I must. The Dragon Vein showed me a path. I need to walk it alone."
I understand. I do not like it, but I understand. She lowered her great head, pressing it against his chest. Come back to us, Seiji. The she-cat will worry. I will worry. The house will feel empty without your brooding presence.
"I do not brood. I observe with clinical interest."
You brood. Accept it. Her golden eyes were warm. Go. Learn whatever you need to learn. We will protect the village in your absence. We will protect each other. And we will be here when you return.
He touched her silver fur, his cold hand gentle. "Thank you, Akane. For everything."
Always, Seiji. I will always be here.
He walked out of the village and into the wilderness, heading east toward the rising sun. The path ahead was uncertain. The training would be brutal. But he had faced worse. He had faced Kage and walked away. He had stopped the strongest spear with his own body. He would master Sage Mode, and he would return home.
Whatever the cost.
The first month was the hardest.
Seiji found a remote valley in the mountains of the Land of Fire, far from any human settlement. The natural energy here was strong—he could perceive it through his Tenseigan, golden threads pulsing through the earth, the trees, the very air. He built a small shelter of stone and wood, a hermitage for the long training ahead. And then he began.
The Dragon Vein's knowledge had shown him the theory. Natural energy was the lifeblood of the planet, flowing through all things, binding the world together. To use it, a shinobi must draw it into their body, balance it with their own physical and spiritual energy in exact proportion. One part natural energy, one part physical energy, one part spiritual energy. The result was Sage Chakra—a power that enhanced all abilities tenfold.
But the balance was treacherous. Draw too little natural energy, and the Sage Mode would not activate. Draw too much, and the natural energy would overwhelm the user's own chakra, transforming them slowly—and then permanently—into stone. The petrification was irreversible. It was death by petrification, the body becoming a statue of itself, frozen forever.
Seiji began with meditation. He sat motionless for hours, his Tenseigan perceiving the flow of natural energy around him, reaching out with his own chakra to touch it, to guide it. The energy resisted. It was not like ordinary chakra—it was wild, untamed, indifferent to human will. It flowed where it wished, and when Seiji tried to draw it into his body, it slipped through his grasp like water through fingers.
He did not grow frustrated. Frustration was a distraction. He analyzed his failures with cold precision, adjusting his approach, refining his technique. By the end of the first week, he could hold a single thread of natural energy within his chakra network for a few seconds before it dissipated. By the end of the second week, he could hold it for minutes. By the end of the first month, he could draw enough natural energy to feel the Sage Chakra beginning to form—a faint, golden warmth at the edges of his awareness.
But the balance was still beyond him. The natural energy kept slipping, the proportions refusing to stabilize. Twice, he drew too much, and felt the petrification begin—a cold numbness spreading through his limbs, his skin turning gray and rough. He expelled the energy just in time, his heart pounding, his body trembling with the nearness of death.
He did not give up. He had faced worse.
The second month brought progress. Seiji learned to still his mind completely, to become a vessel for the natural energy rather than trying to command it. The Dragon Vein had told him: You can command us. But command was not the way. The natural energy could not be forced. It had to be accepted. Balanced. Harmonized.
He began to understand. The cold precision that had served him so well in battle was a hindrance here. Sage Mode required a different kind of focus—not calculation, but intuition. Not control, but surrender. He had to let the natural energy flow through him, trusting his body to find the balance, rather than forcing it with his will.
It was the hardest thing he had ever done. He had spent his life honing his control, shaping himself into a weapon of absolute precision. Surrender felt like weakness. But it was not weakness. It was a different kind of strength.
By the end of the third month, he achieved Sage Mode for the first time.
It lasted only thirty seconds. The golden chakra blazed through his network, enhancing his perception, his speed, his power. His Tenseigan flared with light, perceiving threads he had never seen before—the connections between all living things, the pulse of the planet itself. He felt, for the first time in his life, truly connected to the world around him.
And then the balance slipped, and the petrification began. He expelled the natural energy, gasping, his limbs tingling with the remnants of the transformation. But he had done it. He had touched Sage Mode. He knew it was possible.
He trained through the night, and the next day, and the day after that. Thirty seconds became a minute. A minute became five. Five became ten. The balance grew steadier, the petrification less frequent. His body was learning, adapting, finding the harmony between self and world.
He wrote to Mikoto at the end of the sixth month, a brief letter carried by a hawk he had befriended in the valley.
Mikoto,
I am alive. The training progresses. I achieved Sage Mode three months ago, but it is still unstable. I can maintain it for ten minutes at most, and the petrification remains a danger if I lose focus.
I think of you often. Not in the way poets describe. In the way I calculate my survival. You are my anchor. My reason for enduring this solitude.
Wait for me. I will return when I am ready. I will have tea with you. I still won't enjoy it.
Seiji
The hawk returned weeks later with her reply, the paper worn from the long journey.
Seiji,
I read your letter seven times. I'm glad you're alive. I'm proud of you. The village is quiet—Danzo schemes, but he cannot touch us while Akane watches. She misses you. The koi have been clustering at the far side of the pond for months. Even they can sense your absence.
Come home when you're ready. I'll have tea waiting. I know you don't enjoy it. That's not the point.
I love you. Come back to me.
Mikoto
He folded the letter and tucked it into his inner pocket, next to his heart. Then he returned to his training.
The second year brought mastery.
Seiji spent the first year learning to balance the natural energy. The second year, he learned to wield it. Sage Mode enhanced his already formidable abilities tenfold. His Tenseigan's perception extended miles beyond its normal range, perceiving threads so faint they had been invisible before. His bone techniques, infused with Sage Chakra, became harder, sharper, more resilient. His Severing Threads could cut deeper, reaching into the conceptual bonds that ordinary chakra could not touch.
He developed new techniques. Sage Art: Bone Dragon—a massive construct of reinforced bone, animated by natural energy, that could fight independently. Sage Art: Heaven's Judgment—a variant of Kirin that drew not only on atmospheric lightning but on the natural energy of the planet itself, creating a strike of absolute, primal fury. Sage Art: Restoration—a healing technique that used natural energy to accelerate regeneration far beyond his Kaguya blood's normal capacity.
And he learned to maintain Sage Mode for hours at a time, the balance between self and world becoming second nature. The petrification no longer threatened him. He had become one with the natural energy, a living conduit for the planet's power.
At the end of the second year, he knew he was ready. He had achieved what he set out to achieve. He had mastered Sage Mode. It was time to go home.
He left the valley at dawn, walking through the forest he had come to know as intimately as his own body. The hawk that had carried his letters flew overhead, a silent companion. The sun rose over the mountains, painting the world in shades of gold and amber.
And Seiji, the cold blade, the White Bone Baku, the Sage of the Dragon Vein, walked toward Konoha. Home. Mikoto. His family.
He was ready.