The next morning, Tsunade led Senba to the Hokage Building. She stopped at the door, where a wooden sign read "Hokage Office."
She pushed it open without knocking, yelling, "Old man, I brought him!"
Inside, three people sat in the reception area. The Third Hokage, Hiruzen, was in the center, in his white robes and red hat.
To his left was an older man, Sarutobi Sasuke, Hiruzen's father and advisor. His hair and beard were white, but his posture was straight, and his eyes were sharp.
To Hiruzen's right sat Senju Momoka, whom Senba had met before.
All three looked towards the door. Hiruzen set down his documents and smiled. "You're finally here. Come and sit."
Tsunade strode in and dropped onto a sofa, crossing her legs. Senba followed, stopping before the three leaders and giving a slight bow.
"Lord Hokage, Lord Sasuke, Lady Momoka."
Hiruzen nodded with a warm smile. "No need to be so formal. You must be Senba. Kagami's nephew, and Tsunade's new student."
"Yes, Lord Hokage," Senba replied.
Sarutobi Sasuke sized him up, while Momoka nodded in greeting.
"Tsunade has already told me the situation," Hiruzen said. "You've created a seal-less, A-rank ninjutsu and wish to contribute it to the village?"
"That's right," Senba confirmed. "I call it the Rasengan. Because it's a rotating sphere of chakra."
"Then let's see it."
Senba raised his right hand. Chakra surged, and a swirling blue sphere appeared in his palm.
The three leaders narrowed their eyes.
Hiruzen leaned forward, his gaze fixed on the rotating sphere. His father, Sasuke, seemed to be sensing the chakra flow. Momoka's expression remained neutral, but a flicker of approval crossed her eyes.
A moment later, Senba dispelled the jutsu.
Hiruzen nodded, then reached for a massive scroll on his desk—the Scroll of Seals. He unrolled it on the table, picked up a brush, and dipped it in ink.
"Explain the training method."
Senba detailed the principles of the Rasengan: the rotation, compression, and maintenance of chakra, and how mastery of shape transformation allowed for its activation without hand seals. Hiruzen listened intently, recording every detail on the scroll.
Finally, he set down his pen and looked at Senba with a gratified smile.
"Uchiha Senba, thank you for your contribution to the village. As a reward, you may learn three A-rank ninjutsu from this scroll. You will also receive a bonus of five million ryo."
Senba bowed again. "Thank you, Lord Hokage."
Hiruzen stood and walked over, patting the boy's head with the easy warmth of an elder.
"You are Kagami's nephew and Tsunade's student. We are all family here," he said with a smile. "You can learn any jutsu you wish. Don't be shy."
Tsunade groaned, unable to watch the sweet scene. "Agh, please. Save that for naive kids."
Hiruzen shot her a glare, but she ignored it, moving on to another matter.
"Old man, I'm cashing in the records for fifteen S-rank missions. That, plus his reward for learning three A-rank jutsu. I want to trade it all for one S-rank ninjutsu for Senba."
Senba clenched his fist, silently noting this favor.
Hiruzen glanced at his advisors. Even as Hokage, he had to respect their opinions—and even though Sasuke was his father, they didn't always agree. Their disagreements usually turned into shouting matches.
The two advisors looked at each other and nodded in unison.
"To contribute a self-created jutsu to the village shows the boy is not selfish," Sasuke said. "The village should not be cheap with him."
Momoka nodded her agreement.
Hiruzen smiled and looked back at Senba. "Then which S-rank ninjutsu do you wish to learn? I assume Tsunade told you about the ones in the scroll?"
Senba nodded, his expression serious. "I want to learn the Flying Thunder God Technique."
Hiruzen's eyebrow shot up. The Flying Thunder God? The Second Hokage's signature space-time ninjutsu was notoriously difficult. No one besides Tobirama himself had ever truly grasped it.
And yet, a six-year-old boy was asking for it as his first choice.
Was he a fool?
Tsunade was a bit surprised but didn't interfere. On the way here, Senba had asked her about the technique, and she had given him a brief introduction.
Sasuke looked at him with scrutiny, while Momoka seemed lost in thought.
Senba didn't explain much. With the neural reflexes and observational skills from his MAX-level Gambling Techniques, his reaction speed was even more terrifying than the future Minato's.
If the future Minato could shine in the Third Great Ninja War using the Flying Thunder God Technique, then he, with his talent, could certainly use it even better.
He had originally wanted to learn the Yin Seal, which stores Chakra for critical moments. He would be at the Ninja Academy for the next three years, and with several years left before the Second Great Ninja War, he'd have enough time to store a large amount of Chakra.
But Tsunade had said the Yin Seal was her grandmother Uzumaki Mito's technique, and she could teach him that, so there was no need to waste this opportunity. Thus, he chose the Flying Thunder God.
Hiruzen was silent for a few seconds, then nodded. "Very well."
He spread out the Scroll of Seals again, turned to the page recording the Flying Thunder God Technique, and picked up a blank scroll to copy it.
His pen tip moved quickly, copying the training methods, precautions, and research notes left by the Second Hokage, word for word.
A few minutes later, he put down the pen and handed the scroll to Senba.
"Read it here. After you memorize it, the scroll must be destroyed. Then, Lady Momoka will place a sealing technique on your brain before you can leave."
Hiruzen explained: "The purpose of that sealing technique is to prevent others from viewing your memories, which would lead to the leakage of the Flying Thunder God Technique's training method."
He paused and continued: "As for oral transmission, although there is no such restriction, teaching the Flying Thunder God Technique to others without authorization will also be punished and considered treason. You will be directly designated as a rogue ninja."
"I understand." Senba nodded and took the scroll to read.
The office quieted. Hiruzen returned to paperwork, while Tsunade leaned on the sofa, closing her eyes to rest.
Senba focused on reading every word on the Ninjutsu scroll, engraving the complex techniques, chakra flow paths, and methods for marking spatial coordinates into his mind.
Only after half an hour did he close the scroll, reviewing all the information.
"I've finished reading."
Senba handed the scroll to Hiruzen, who formed a seal and caused the scroll to turn to ashes.
Meanwhile, Momoka stood up and walked over to Senba. "Do not resist."
She pressed her index and middle fingers together, tapping them on Senba's forehead. A gentle wave of Chakra probed into his mind, laying an invisible barrier deep within his consciousness.
A moment later, she withdrew her hand and nodded: "It's done."
Senba bowed slightly. "Thank you, Lady Momoka."
Momoka nodded and returned to her seat.
Hiruzen said with a smile: "Although the Flying Thunder God Technique is very difficult to learn, don't be anxious; practice slowly. If there is anything you don't understand, you can come and ask me, or you can ask Tsunade, although neither of us can use it."
Tsunade glared at him, but Hiruzen only laughed out loud.
"If you want to learn the Flying Thunder God Technique, you must have specially made Kunai," Momoka kindly reminded him.
"Although the Flying Thunder God Technique allows for instant teleportation, it must be positioned using the Flying Thunder God Mark. Ordinary Kunai can also be engraved with the mark, but the Chakra conduction effect is very mediocre."
Momoka paused and continued: "In that situation, even if you can teleport, there will be a delay of one or even two seconds. In battle, this delay could be fatal."
Senba nodded thoughtfully and asked: "So, I must use specially made Kunai?"
"Yes." Momoka nodded, "You need Kunai plated with chakra metal; one costs about 100,000 ryo."
She looked at Senba with a gentle gaze, "You can buy one to practice with first. If you can learn the Flying Thunder God Technique, then you can order them in bulk."
Senba noted it down seriously, "Understood. I will buy a specially made Kunai when I go back; the ninja tool shop should sell them."
"Alright, let's go." Tsunade stood up, waved at the three, then left the Office with Senba.
After the door closed, Hiruzen's gaze fell on the Hokage Rock outside the window.