At the heart of every authentic katana lies tamahagane. This was a truth Tenji respected.
Tamahagane was not ordinary steel. It was born from iron sand - kanze -smelted within a traditional clay furnace known as a tatara. Tenji went right ahead, placed his things in the corner, he didn't have much anyway, and then began. The process usually lasted upward of seventy-two hours, during which fire, earth, and human endurance were combined to bear fruit as tamahagane.
When the furnace was finally broken open, the result was not a single uniform metal but a fractured constellation of steel: some pieces rich in carbon and brittle, others soft and resilient, each holding a different 'fate' as Tenji liked to say.
To a swordsmith, this chaos was sacred.
Tamahagane was rare, expensive, and painstaking to produce. It was not mass-made, nor easily replaced. For millennia, it had been regarded not merely as material to use for smithing, but as something alive. Literally raw potential awaiting someone to form it. Samurai believed their souls resided in their swords, and swordsmiths treated tamahagane as the soil from which that soul would grow. Quite poetic, but humans liked to be.
Tenji, however, was different from others. He had studied the art of smithing and, of course, blade creation during his adolescence. He came to appreciate the process, as it had a calming effect. It was special to create something like that. In fact, it was Tenji who had developed the swordsmithing method used to create modern katanas and who had taught it to the swordsmiths living in the Land of Ancestors over 1000 years ago.
The way to create a proper katana was passed down from smith to apprentice, and therefore a closely guarded secret. They were adamant about keeping the traditions alive and doing everything as they had been taught. Tenji was, of course, different. He had come up with the method; he could, of course, change it again. And that he did.
He was no longer limited in his approach since he had the power of chakra.
Instead of using the preheated flames in the forge, Tenji put them out and created his own, using his chakra. But he didn't stop there; he used Sage Power and infused it into his flames, coming up with a new potential jutsu on the spot.
'Sage Art: Fire Style: Pure Fire'
Tamahagane was not ordinary steel. The iron sand - kanze - was placed inside the tatara and smelted. A process which was supposed to take 72 hours took considerably less time. Tenji didn't rest; he didn't need to. He was constantly using the Sage Fire while also nourishing his cells with the energy.
The swordsmith shook his head and told Tenji to stop, but he said that he should wait until he had the Tamahagane in his hands before he judged. When the man touched the steel, he tested it by fracture and sound. And what he found shocked him.
"This is... Tamahagane. But how?" he asked.
Tenji didn't answer the man and took the material from him, checking it with his powerful senses. The steel revealed everything about itself: carbon gradients, internal stresses, hidden impurities, and latent strengths were all laid bare as clearly as muscle tissue underneath skin. It was far better than anything he had created before his death.
Tenji selected only the finest slices — those with the perfect balance of hardness and flexibility —and set them aside. The rest, though valuable by usual smithing standards, were dismissed without hesitation. Seeing his dismissal of the best material he had ever seen, the smith nearly choked and picked it up as though it were sacred. Tenji did not care in the slightest.
Before forging truly begins, tamahagane must be purified. Traditionally, or the tradition that developed from Tenji's teachings, the steel was folded and hammered repeatedly, often as many as 15 times, creating thousands of layers. This process expelled impurities and redistributed carbon evenly throughout the blade, ensuring it would neither shatter from brittleness nor dull from softness.
Tenji followed this principle, but not to a T. He used the Sage Fire again, sustained by his chakra and nature energy. It burned with great heat and consistency, without fluctuation of temperature.
As the steel reached forge-welding temperature, Tenji folded it like he had come up with 1000 years ago.
Once, twice, thrice... again and again.
The smith and his apprentices almost had their eyes pop out of their sockets. Each fold appeared flawless. There was no trapped air, no uneven bonding, no carbon loss. Where traditional smiths required many repetitions to correct different imperfections, Tenji needed only a single try to get it perfect. He folded the steel seven times because his feeling told him that further folding would weaken what was already excellent.
From this process emerged the hada, the grain pattern etched into the blade's surface. Unlike the identifiable styles of known schools, Tenji's hada followed no lineage. It was unique solely to him. But little did he know that was an indicator in itself.
"This hada... could it be...? No, no, that's not possible... is it?" the swordsmith asked himself.
He had studied swordsmithing long ago and was well aware of the different levels of smithing. There were apprentices, who knew almost nothing and were helpers, and then there were those adept and the true masters. But even among the masters, there existed different skill levels. The various styles and techniques were known. The one he saw now was equivalent to what Hashirama was to normal shinobi.
.
Once folded, the steel was to be shaped into a billet. Tenji infused Sage Power into the steel as he did, as structural reinforcement. Every step he took, he did that as an experiment to see what he could create. And so far, he felt that he would create his greatest masterpiece yet.
The blade took shape gradually beneath his hands: spine, edge, ridge line, and tip formed as Tenji worked. He did not force a curvature into the steel; he kept it straight.
Before the next step, which was called quenching, traditional swordsmiths applied a clay mixture to the blade. The edge was then coated lightly or left exposed, while the spine received a thicker layer. When quenched in water, the exposed edge cooled rapidly, becoming hard, while the insulated spine cooled slowly and remained flexible.
This technique produced the hamon, the visible temper line running along the blade.
Tenji did not use clay.
Instead, he replicated its function with chakra, using 'Sage Art: Water Style' to achieve a greater effect. When Tenji quenched the blade in the water, the transformation was seamless. The blade curved naturally as martensite formed along the edge, while softer structures remained in the spine.
"...There was no cracking," the smith was in awe.
"What do you mean?"
"This hamon... is unlike any I have heard of. I am now more convinced than ever."
After quenching, the katana was polished. Again, this process usually took weeks of meticulous work with progressively finer stones, but Tenji performed this himself. He once again Sage Power to create the stones to polish the edge to perfection. When the process was finally finished, citizens of the Land of Iron had arrived over the last two days and were staring at the most perfectly crafted katana the world had seen to date.
Tenji turned to the smith and presented the blade professionally. He was happy as well. Not only had he managed to adapt the forging process he had come up with before he died, but he also noticed what a brilliant blade he truly made. As a test, he infused his chakra into the blade. Like a powerful stream, his chakra flowed through the blade equally.
Usually, the best blades were those which were made from chakra metal. These types of weapons allowed a user to flow their chakra into them, granting them additional properties. Depending on the nature of the transformation, there were a lot of combinations of jutsu shinobi used. It was impossible to create swords or weapons that conducted chakra as well as those made from chakra metal. And yet, as Tenji fuelled his chakra through the katana, it lit up brightly.
"That's... impossible!"
A commotion took place, and several Samurai pushed their way through the crowd. Among them was their leader. When they arrived, they looked around to understand what was happening and then turned to the smith.
"What's going on here? Why are there so many people in the forge?"
"General Mifune! I apologise for this, but... well... something happened," the smith said.
Mifune was a samurai warrior and the General of the Land of Iron. He had arrived today to ask about another batch of weapons from the smiths when he saw the large crowd. As the most skilled samurai of the Land of Iron, he recognised what the 'reason' for the commotion was. He looked at Tenji holding the katana, and his eyes widened.
"This... who made this?!" he asked.
"I did," Tenji answered and then turned to the smith.
"Well? What is your verdict?" he asked.
"Uhh... If you allow me to ask you, what is your name?" the smith asked.
"Hm? Tenji, why?"
"Tenji, huh... That's what I thought."
"Your name is truly Tenji?" Mifune asked.
"Yes, why is that of importance?" Tenji asked.
"For centuries, the art of swordsmithing had been refined and improved. Each smith always tried to create the perfect blade, the one without impurities, perfectly balanced and as sharp as any of the Kusanagi. Or so we told ourselves. In truth, all we try to accomplish is to reach what the first swordsmith managed. According to legend, the original swordsmithing style was passed down from master to student alone, and there was only one master in each generation. But it was lost in history, and all over the world, we are trying to achieve the same level of quality blades as the original."
Tenji looked at the smith with a neutral expression. He didn't know what they were talking about and, honestly, didn't really care. But he still listened to the two. Mifune was the one to continue.
"According to legend, this mysterious style was called the Tenji-style. Some claim that it doesn't matter now, since the Kusanagi blades and those of the Seven Swordsmen of the Mist are better, but I disagree. Are you a user of the Tenji-style smithing?"
"Uhh... sure."
"I thought so. My name is Mifune. I am the leader of the Samurai and the General of the Land of Iron. I would like to invite you."
.
Mifune and Tenji sat opposite one another, sipping tea. No one said anything. Mifune allowed his guest to enjoy the tea first and relax a bit before he addressed the reason for the invitation. The experienced samurai studied Tenji's posture and movements, and thought about what he had seen and heard before. It only made him more curious to see someone he was convinced was a member of the 'renowned' Tenji-smithing line, who was also a fighter. Because of that, Mifune was sure that Tenji was a warrior.
"So, why did you wish to speak to me, Mifune?" Tenji asked, not using any honorifics.
"I would like to ask whether you belong to any of the five great nations, or if you are affiliated to any of the smaller lands?"
"I do not."
"I see. You see, Tenji-san, seeing the katana you created has made me think. War has already erupted on almost all borders, and the way things are going, the great nations will soon officially declare it as well. The Third Great Shinobi War is upon us. The Land of Iron is a neutral country, having long taken another path than that of the shinobi. But even as a neutral country, we need to protect our borders and prepare our forces and equipment to defend our land. But we lack those things right now, more than ever.
I was wondering: if you truly do not belong to any of the other countries, would you be willing to craft the weapons for us? Naturally, the Land of Iron would pay you for those services and provide all the materials needed."
Tenji took a sip of his tea and thought about it. Truthfully, after he had created the katana, he thought about experimenting further and maybe making more swords of different kinds. So this would allow him to do that. It would also allow him to act on his ideas for combining chakra and jutsu with his swordsmanship. From what he saw and how Mifune moved, he was an experienced master of kenjutsu. But whether he could provide sufficient challenge to help him test his advancements would have to be seen. After a moment of thought, he answered.
"Very well, I can do that. However, I have conditions."
"What kind?"
"I will leave when I choose to. This may be tomorrow or in a year. But I am allowed to leave at any time, no matter how many weapons I have already created. That's a risk you will have to take."
"Naturally, we agree on that," Mifune said.
"I will require a place to stay and a place to test out certain... things. Grant those, and we are all set."
"Those are easy requirements, Tenji-san."
Tenji grinned. He had gotten more from this deal than Mifune realised, and it would only help him in the long run.