Nintaijutsu

"Ha ha ha ha ha!"

Old Man Shiyu let out a malicious laugh of schadenfreude from the side.

At the end, he said, "Insect Princess, do your best on your own. This old man won't be keeping you company."

This old man had become an old geezer.

With that, he leaned on his walking stick and ambled away.

Mimi glanced at Old Man Shiyu.

Once ninjas reached a certain age, their physical condition rapidly declined. Most of it was because they had frequently used Chakra in their youth, overdrawing their bodies' natural lifespan.

Living into one's fifties or sixties was already considered a long life.

In the Warring States era, the average lifespan was around thirty.

It was perfectly normal to go to the battlefield at five or six years old.

Among them, due to the Aburame clan's secret Nest technique, this physical condition was even more severe.

Even though Old Man Shiyu had kept putting up a brave front, Mimi had known since yesterday that he was already running out of energy.

Just as he had said himself, he did not have many years left to live.

He was, after all, one of those short-lived people who began Nest Building in infancy. Who knew what vital organs he had damaged?

Because of this, most of the Aburame clan did not excel in taijutsu.

Compared to ordinary ninjas, the Aburame clan's physical strength was simply too poor.

Watching Old Man Shiyu's departing back, Mimi climbed up from the ground and looked at Old Man Shiki.

That was why Mimi hated the eager, expectant looks from her elders. She really could not ignore them.

So she could only work desperately hard herself.

Though it sounded like she was training for Old Man Shiyu's sake, Mimi had her own pace to follow as well.

"Did you see it clearly?" Old Man Shiki asked.

"Your arms are longer than mine," Mimi said gloomily.

With her current short, squat body, she was at a disadvantage in every way.

"What else?"

"Your wrist strength is greater than mine."

"Then what are your own strengths?" Shiki asked.

"Agility?" Mimi replied.

"Barely," Old Man Shiki said. "What else?"

"I think I should use a weapon. A sword or something," Mimi said. "Grandpa Shiki, you wouldn't mind, would you?"

"A weapon?" Shiki said. "Swordsmanship is also a form of taijutsu."

"Very good."

As he spoke, the battle between the insects on the microscopic level came to an end.

The venomous insects Shiki had sent into Mimi's body through his attack were completely shredded.

On the surface, the purple coloring on Mimi's hand merely squirmed for a moment before settling down.

The same was true for Shiki's hand. While attacking, he had also been attacked by Mimi.

Old Man Shiki glanced at his hand and said, "As long as there is physical contact, you will be attacked. Ordinary ninjas would be killed very quickly."

"What about extraordinary ninjas?"

"You won't be able to touch them," Old Man Shiki said from experience.

"Therefore, my taijutsu is about finding a way to touch the opponent."

"As long as I plant the venomous insects, I win."

What wonderfully straightforward taijutsu.

"Attaching Nano Kikaichu to metal can be done, but it is very difficult."

"However, if it is Insect Princess, it should not be a problem."

"And Insect Princess, your wrist strength is too weak. That is partly because you are from our Aburame clan, and since you are a girl, your wrist strength is even more lacking. Avoiding direct clashes should be the basis of your taijutsu."

"Making use of a weapon's advantage is not a bad method."

"But the weight of a sword would be no small burden for you."

"Isn't there a lighter sword?" Mimi asked.

Straightforward was good. Straightforward meant simple and easy to learn.

After pondering for a moment, Old Man Shiki looked toward Old Man Shiho.

Brother, what do I do if I don't know swordsmanship?

Old Man Shiho said, "I do have some lighter swords."

As he spoke, he released a cluster of Kikaichū to deliver a message.

"When I was young, this old man collected quite a few things like that. If there's anything else you want, just tell Grandpa."

"Thank you, Grandpa." Mimi smiled sweetly.

"Insect Princess." Old Man Shiki spoke, drawing Mimi's attention back. "Because Nano Kikaichu are so tiny, their wings have degenerated. They can't move quickly through flight and can only infect others through close physical contact."

"So, do you know how to expand the Nano Kikaichu's attack range?"

Mimi thought for a moment. "Wind!"

It was common knowledge that viruses could spread through the air.

If they could only drift and had difficulty moving on their own, then she could borrow the power of the wind.

"Correct." Shiki said, "There is something called Nintaijutsu, taijutsu activated through the power of chakra natures. It is more powerful than ordinary ninjutsu."

"Because I was at a disadvantage in arm strength, I could only find a solution through speed. This Nintaijutsu was born for that reason."

"But to master this Nintaijutsu, the first thing you must grasp is wind nature transformation."

"Insect Princess, what do you think wind is like?"

"What is wind like?" Insect Princess considered it. "A change in temperature."

"Huh?" Old Man Shiki had a head full of question marks as he looked at Old Man Shiho.

Brother, I have no idea what she's talking about.

Wasn't wind supposed to be sharp?

"A change in temperature?" Old Man Shiho asked. "Why do you say that?"

"Wind is caused by the sun's Heat Radiation. Sunlight shines upon the ground, the air near the surface heats up and rises, and colder air from the sides flows into the gap. That circulation of air is wind."

"Insect Princess, you're describing a natural phenomenon. Chakra simulates the form of wind, so it can follow your imagination," Old Man Shiho said.

Old Man Shiki extended a hand. Without forming any seals, a gust of wind rose from his palm, carrying purple smoke into the air.

"Wind is a very rare Chakra attribute. During testing, if the test paper is cut in two, it means you have a wind attribute. Thus, most people believe wind's nature transformation is tearing and cutting."

"And people often understand the direction of the wind as wind's shape transformation. That isn't exactly wrong."

"However, wind's shape transformation also conceals a nature transformation—the speed of the wind."

As he spoke, Old Man Shiki suddenly took a deep breath, then violently expelled a vast cloud of purple mist from his mouth.

"Speed is power!"

"This is Signless Ninjutsu."

Mimi narrowed her eyes.

Wasn't that momentum? Or rather, it could be called a vector.

It was a physical quantity defined by an object's mass and velocity, referring to the effect produced by a moving object.

Something like Asuma's Wind Blade—its nature transformations of sharpness and thinness—was essentially an application of vectors.

And the wind speed Old Man Shiki spoke of referred to mechanical motion.

An object's mechanical motion did not occur in isolation. It interacted with surrounding objects, manifesting as the process through which mechanical motion was transferred between the moving object and its surroundings.

Momentum was precisely the physical quantity that measured mechanical motion from the perspective of its transfer.

The result of that transfer was that total momentum remained unchanged.

To put it more simply and vividly, fanning the air with a fan was a process of transferring mechanical motion.

The harder one fanned, the stronger the wind.

Here, Chakra replaced the fan and interacted with the surrounding air, creating powerful winds.

I get it!

Mimi suddenly pressed her hands together, inhaled, and exhaled.

No purple mist came out.

A mouthful of Nano Kikaichu mixed with saliva was swallowed back down by Mimi.

Her hands said: No, you still can't do it.

Mimi awkwardly lowered her hands.

"You understand?" Shiki asked.

"I was just trying it," Mimi said.

"The key lies in applying pressure over an area to cause greater oscillations in the wind." Shiki shared his experience. "You need to practice more."

"Mm." Mimi nodded obediently.

She raised a hand to adjust her mask. This mask needed modifying. It mainly covered her mouth and affected her ninjutsu.

"Once you can do this, you can cultivate my secret Nintaijutsu. And Insect Princess, you possess wind-release Chakra, which saves you a great deal of trouble."