(Edited)
In the training grounds of the Senju clan, Tobirama's disciples met for the first time after Madara's incident. From this point forward, they shared a closer bond, much stronger than when they were merely classmates at the Konoha Academy. As Uchiha Kagami and Fumori Masaki arrived, Sarutobi Hiruzen was the first to greet them. He acknowledged Kagami, the heir to the Uchiha clan, then turned to Masaki, whispering playfully.
"Masaki-kun, how are things with your new wife? You finally tied the knot. You must be enjoying married life," Hiruzen chuckled, knowing that Masaki had his marriage ceremony. He couldn't resist teasing him.
"Hiruzen-kun, you're really curious about my personal affairs, aren't you?" Masaki replied with a smile. Back at the Academy, he hadn't been particularly close to Hiruzen. Now, he found his personality a bit unpredictable. No wonder, he thought, Hiruzen would later have a student with a penchant for gambling, immortality, and other unseemly habits, this one masaki thinks inherited by Hiruzen himself.
"Haha, I'll drop it," Hiruzen said, sensing Masaki wasn't in the mood to discuss his private life. Shifting topics, he added, "Masaki-kun, since we're all under the same master now, let's be less formal. Call me Hiruzen."
Masaki nodded, "Alright, Hiruzen it is."
"Good! Masaki!" Hiruzen said warmly, patting Masaki on the shoulder.
At that point, all seven of Tobirama's disciples had gathered. They were becoming closer, eager to discuss what advanced techniques Tobirama would teach them. Though he had been a teacher at the Academy, Tobirama had only taught general lessons to the entire class. Now, as his direct disciples, they would have the privilege of learning his personal skills.
While everyone was engrossed in conversation, Tobirama's voice interrupted them. "It looks like you're all getting along."
They turned to see Tobirama approaching. The group quickly stood and bowed in respect. Tobirama glanced at his seven students with satisfaction. Both he and his elder brother had high expectations for this group, and Tobirama knew he would have to be strict to bring out their potential.
"Although you're all my direct disciples, my elder brother, Hashirama, is also your sensei. He will come to guide you when he has time," Tobirama explained.
There had been some surprise when the list of disciples was first announced. People wondered why Hashirama didn't take on any personal disciples himself. However, Hashirama had made it clear—Tobirama's disciples were also considered his, and he would instruct them whenever possible.
The group felt relieved. They were excited about the possibility of receiving guidance from the First Hokage himself. Without his instruction, they would have been a bit disappointed.
Masaki, however, was less surprised. Hashirama had already guided him multiple times, especially in his study of the Sage Arts.
Tobirama wasted no time and began preparing them for today's practice. When Hiruzen asked who would receive instruction first, Tobirama simply said, "I will guide all of you at once."
Everyone was momentarily stunned. How could one person instruct seven people simultaneously? Masaki couldn't help but think of the advanced techniques Tobirama was known for. Could it be...?
With a quick hand sign, there was a loud "bang," and six identical Tobiramas appeared beside the original. At first, the others thought it was a simple clone technique, but then they recalled rumors about a groundbreaking jutsu developed by their sensei.
"Sensei, is this the Shadow Clone Technique you created?" Hiruzen asked in awe.
"That's correct," Tobirama replied. "Each clone is a physical entity, essentially another me. This way, each of you will receive one-on-one guidance. There's no need to take turns."
"Amazing..." Hiruzen murmured, astonished at the sight of the six identical Tobiramas.
"If you're impressed, don't be," Tobirama said indifferently. "You'll all learn this jutsu in time."
With seven Tobiramas now present, each disciple followed one to different areas of the training ground. Masaki followed one of the clones, admiring his sensei's mastery. He knew the Shadow Clone Jutsu would have a lasting impact on the ninja world, and future generations would use it in incredible ways.
"Masaki," Tobirama said, turning to face him. "You have a natural aptitude for the Sage Arts, but I can't teach you those techniques. That's my brother's domain. What I will focus on is refining your Wind Release ninjutsu and your clan's swordsmanship."
The Fumori clan was known for their expertise in swordsmanship, paired with Wind Release ninjutsu. Tobirama's plan was clear: Masaki would specialize in these skills. Clan heritage should be prioritized. Understanding this, Masaki nodded. "Understood. Please guide me, Sensei."
"Good," Tobirama continued. "First, I'll pass on my knowledge of swordsmanship. You should also consider expanding your chakra nature training. Right now, your focus on Wind Release is correct, but having only one chakra nature is limiting. To truly excel, you should master at least one more, so you can combine them effectively in battle."
Masaki thought deeply. Could he manage a second chakra nature? Kakashi once mentioned that most Jōnin were proficient in two nature transformations, but during the Warring States Period, such expertise was rare. Still, Masaki knew this would be vital in the future.
Seeing his student deep in thought, Tobirama reassured him. "Don't worry, you can take your time considering it. For now, let's begin swordsmanship practice."
Tobirama handed Masaki a specialized short-edged sword. While Masaki's clan favored swift, one-strike assassinations, Tobirama's style was more versatile, emphasizing both stealth and head-on confrontation. He guided Masaki on how to use the Fumori sword in various combat situations.
As training began, Masaki quickly realized that this was far more intense than anything at the Academy. While those sessions had been tough, they paled in comparison to Tobirama's rigorous regime. Masaki felt like he had stepped into a world of relentless training—hell, even.
Despite the grueling pace, Masaki appreciated it. He could feel his strength increasing daily. Tobirama's teachings seamlessly blended with his clan's sword techniques, creating a refined, powerful fighting style. Though Tobirama wasn't proficient in Wind Release, his unique insights still helped Masaki sharpen his control over the element.
Relying on the Senjutsu chakra to provided Sage Techniques, Masaki could keep up with the intense training, even if his talent wasn't on par with some of his peers. However, despite his progress, he felt as though he had hit a wall. His mastery of Sage Mode had improved, but it wasn't advancing further.
Hashirama often visited to help Masaki with his Sage training. After hearing Masaki's concerns, Hashirama suggested, "I think your Sage Mode can evolve further, but it's just a guess. It seems related to the coverage of the Sage markings. Right now, they cover your cheeks, but as you've grown stronger, the markings have reduced to just your left side. That's your limit—if you push further, you'll lose control of the natural energy and be consumed by it."
"Master Hashirama, what should I do to increase my control?"
"The key is increasing your chakra reserves," Hashirama said with a smile. "No matter how well you control natural energy, it's your chakra pool that limits your progress."