The next morning, Shinra sat in his living room with an ink brush in hand. A piece of heavy training gear rested on the floor in front of him, the kind some shinobi used to build their strength.
During the mission in the Land of Wind, Shinra had already come close to completely understanding the seal Kurosawa had given him. Unfortunately, one unexpected event after another had kept him from inscribing it onto an item and testing its effects until now.
'No wonder Kurosawa said fuinjutsu was like a never-ending puzzle. If he hadn't given me the scroll with this seal, recreating it would have taken me a very long time.'
The advancement of Fuinjutsu was built upon the work and commitment of countless generations. Each generation inherited the knowledge of those who came before them, added their own discoveries, and passed them on. Shinra had benefited from that process himself, and the more he studied the art, the more he appreciated how much easier it was to build upon an existing foundation than to solve every problem from scratch.
For someone his age, his understanding of Fuinjutsu was already respectable. He could read and analyze seals that would have been incomprehensible to him only a few months ago, and with enough time, he could reproduce many of the simpler ones. He was still nowhere near the level where he could apply seals freely with nothing but chakra, however. According to Kurosawa, reaching that point was one of the requirements for being recognized as a true master of Fuinjutsu.
Shinra still needed the proper ink and brush, and even then, a minor mistake in the pattern could alter the entire function of a seal.
That limitation didn't bother him particularly much. Fuinjutsu was an art where understanding mattered more than talent, and Shinra had plenty of room left to improve.
He dipped the brush into the ink and carefully began drawing the seal onto the training gear. He followed the pattern he had spent weeks studying, paying attention to every connection between the individual sections. He wasn't copying it blindly anymore. He knew where the chakra entered the seal, where it was stored, how the amount of weight was determined, and how the burden was distributed across the body.
There was a certain satisfaction in being able to look at a complicated seal and understand why every part of it existed.
Several minutes later, Shinra finished the final stroke and slowly lifted the brush. The markings remained still for a moment before a faint pulse of chakra travelled through them. The entire pattern lit up briefly, then settled.
Shinra examined it from several angles before finally relaxing.
'It worked.'
He placed the brush aside and looked at the seal again.
His thoughts inevitably returned to the person who had given it to him.
Kurosawa.
Shinra hadn't seen the man in some time, but he remembered the conversation clearly. At the time, the seal had seemed like a money tree. Now, as he finally put it to use, Shinra found himself wondering how much longer Kurosawa would remain involved in his life.
There were too many things happening around him.
The village was approaching another turning point, and Shinra knew where some of those events would eventually lead. The Uchiha clan was one of them.
He knew the fate that awaited them.
Knowing it was almost worse than not knowing.
Shinra could interfere, of course. He could try to alter certain events or save individual people. But aligning himself with the Uchiha wasn't going to be easy, and things could become considerably worse if his actions pushed the clan and Konoha toward an open conflict.
His current strength wasn't enough to shoulder the repercussions.
Even if he somehow managed to expose everyone involved and force the village's leadership to listen, he would still need the strength to deal with the consequences. There were too many variables, too many people with enough strength and authority to make his intervention meaningless.
He had already attracted Danzo's attention without trying.
Getting involved with the Uchiha now would only make matters worse.
'I'm still too weak.'
The thought wasn't pleasant, but Shinra couldn't deny it.
He picked up the training gear.
'In just a month, I will turn eleven. By then, I will only have a year to find a solution.'
The chances of him accomplishing anything were slim.
Even so, Shinra genuinely wanted to save his mentor.
There was nothing he could do about the future today. He could, however, become stronger before it arrived.
Shinra attached four of the new seals to his body and adjusted each one carefully.
"One hundred kilograms."
The seals activated.
The change was immediate.
His knees bent as his muscles reacted to the sudden weight. His shoulders dropped, and his body instinctively shifted its balance to compensate. Four hundred kilograms settled over him in total, twice the weight he had been accustomed to carrying with his old training seals.
Shinra took a step.
His foot came down heavily enough to make the floor creak.
He stopped and looked down.
"…Heavy."
That was putting it mildly.
Two hundred kilograms had gradually become something he could move around with little difficulty. Four hundred was another matter entirely. Even turning his torso required effort, and raising an arm felt as though someone had attached an invisible weight to it.
He remained still for several minutes, letting his body adjust to the burden.
The seal itself was impressive. Its maximum capacity was two tons, meaning that what Shinra was currently carrying was only a fraction of what it could eventually handle.
'Two tons per seal.'
He tried imagining four of them operating at full capacity.
The thought was absurd.
There probably weren't many people in the village who could make use of the seal's full potential. Most shinobi would destroy their bodies long before reaching anything close to that amount.
One person came to mind.
'Might Guy.'
Shinra could easily imagine the green-clad jōnin treating two tons as another challenge to overcome.
'He'd probably enjoy it.'
After allowing himself a few more minutes to adjust, Shinra left the apartment and headed for one of the more isolated training fields.
The field was empty when he arrived. He still surveyed the surrounding area with his sensory technique before beginning, just in case someone was watching.
Shinra preferred it that way. He didn't want his entire arsenal to become common knowledge throughout the village. Keeping an ace up his sleeve was a safety measure, especially after Danzo had already shown an interest in him.
He started with basic movement. Walking became running, running became squats, and eventually he began jumping while carrying the additional weight. None of it was particularly complicated, but the burden changed the nature of every exercise. His muscles had to work considerably harder just to produce movements he normally performed without thought.
After some time, his body began to adjust.
Not completely, but enough for Shinra to move without every step feeling like an effort in itself.
He moved on to taijutsu.
Shinra stopped in front of a thick tree and examined it for a moment. The trunk was wide enough to withstand his attacks without immediately collapsing, which made it a useful target.
His thoughts turned to Tsunade and Sakura.
In the Naruto world, physical strength wasn't determined entirely by how much someone trained their muscles. Sakura was proof of that. Her chakra control allowed her to concentrate chakra into her fists and release it at the precise moment of impact, dramatically increasing the destructive force of her strikes.
Rock Lee could train his body endlessly, but there were limits to what physical conditioning alone could accomplish. Chakra could supplement the body's natural strength and allow someone to produce considerably more force than their physique would suggest.
Shinra already possessed excellent chakra control thanks to his training and mastery of the Rasengan. If anything, that was one of the areas in which he had an advantage over most shinobi his age.
But the Rasengan had taught him something slightly different.
The technique demanded precise manipulation, shaping, and rotation, but he didn't have to coordinate its release with a physical strike landing on a target. Tsunade's method required both to happen at exactly the right moment.
That was something Shinra had never seriously practiced.
He decided to try.
Shinra lowered his stance and gathered chakra in his right arm. He focused on maintaining the flow while accelerating his body forward.
His fist struck the tree.
THUD!
The impact shook the trunk. His fist broke through a layer of wood, and the entire tree trembled from the force.
Shinra withdrew his hand and frowned.
The chakra hadn't reached the point of impact at the right moment.
He tried again.
This time he held it for longer.
THUD!
Better, but still not right.
Another attempt.
Then another.
Each time, he adjusted the timing by a small amount. His chakra control wasn't the problem. He could move the chakra exactly where he wanted it. The difficulty was making the release coincide with the instant his fist actually transferred its force into the tree.
The four hundred kilograms didn't make the problem easier.
If anything, they made it worse.
Every movement required more effort, and the additional weight made the speed of his punch fluctuate depending on how much force his muscles could produce.
Shinra continued anyway.
The tree began to accumulate damage. His first strikes had already torn away much of the bark, exposing the lighter wood underneath. As he continued, his knuckles began punching into the trunk itself, leaving increasingly deep depressions and sending cracks through the damaged section.
Yet he still couldn't achieve the result he wanted.
'It seems I was too overconfident. Learning an application of an S-rank shinobi's technique without guidance is more difficult than I expected.'
He examined his hand for a moment before looking at the tree again.
He could make the timing easier by reducing the amount of chakra flowing into his fist, but doing so weakened the resulting strike too much. Increasing the output created the opposite problem. The greater the amount of chakra he tried to release, the more difficult it became to control the timing precisely.
There had to be a balance between the two.
Finding it would require more practice.
Shinra raised his fist again.
He punched.
THUD!
His fist struck the tree hard enough to bury his knuckles into the damaged wood.
He felt the chakra move through his arm.
Then something caught his attention.
Shinra remained in place.
His eyes narrowed.
The sensation had been subtle, almost too small to notice.
He had felt the physical impact first.
His chakra had followed.
Shinra pulled his fist away and looked at the tree.
'…What was that?'
He wasn't certain.
He closed his eyes and focused on his own body.
His muscles were exhausted. His movements had slowed considerably under the weight, and his arm was beginning to feel heavy. His chakra, however, continued circulating normally.
That was when he noticed the difference.
His body was struggling to accelerate.
His chakra wasn't.
Shinra opened his eyes and tried again, this time paying attention to the exact sequence of events.
He gathered chakra.
Moved.
His fist travelled forward.
THUD!
The moment of impact came first.
Then he felt the remaining chakra continue through his arm.
It was only a tiny difference, but his sensory ability made it possible to distinguish the two.
The training weight had slowed his physical movement enough to make a timing difference that would normally have been almost impossible to notice.
He hadn't lost control of his chakra.
His chakra was simply moving according to his command while his exhausted body struggled to keep pace.
Shinra tried another punch.
THUD!
Again.
The same thing happened.
He stood there for a moment, thinking.
He had been trying to synchronize the chakra with his physical strike to no avail.
But perhaps synchronization wasn't the only possibility.
Shinra gathered chakra into his arm once more.
This time, instead of attempting to release everything at the moment his fist struck, he deliberately kept a small portion contained.
He moved.
His fist crashed into the tree.
THUD!
The trunk shook violently.
Shinra kept the remaining chakra compressed in his arm.
For a fraction of a second, nothing happened.
Then he released it.
BOOM!
The tree lurched.
A deep crack opened beneath his fist and raced upward through the trunk. The bark around the impact point split apart, and for an instant Shinra thought that was all that would happen.
Then the chakra he had held back reached the point of contact.
BOOM!
The damaged section of the trunk collapsed inward. Wood splintered around his fist as the delayed chakra struck through the same point, driving the damage deeper into the trunk and widening the hole his knuckles had already created. A violent crack travelled several feet upward, followed by the sharp sound of wood tearing apart under pressure.
Shinra immediately pulled his hand back.
A sizeable chunk of bark and wood fell to the ground.
He stared at the hole in the trunk.
His first strike had already been strong enough to punch through the bark and damage the wood beneath it. Yet the second impact had driven considerably deeper, arriving after the first blow had already compromised the structure.
Shinra looked at his hand.
'…So that's what happened.'