A/N : Before the Chapter starts, I would like to clear up some things, this version of Naruto is slight AU, with ages and background of different characters along with History of the ninja world changed slightly to suit plot convenience, plus if there is nothing different, I could just be writing any other ff.
Another thing is that the technology of ninja world is comparable to early 1940's without the industrialization. They have TVs, Radio, still use Vaccuum tubes for computation, they have steam engines, electric motors but not widespread electricity.
They however do not possess industrial technology to increase the scale of things (Due to Ninja wars being less dependant on weapons and more dependant on personal strength of a soldier, the growth in these aread were never fuelled by wars as such they remained under developed)
As such, Hiro is taking advantage of that fact to establish himself as an Industrial Tycoon, using technology and management techniques of the 21st century.
## Chapter ##
Hiro woke up late today, it was already past noon by the looks of sun rays coming through the window.
'Last night was crazy' Hiro thought, Hinata had never been so proactive in the night before.
She woke up, almost 3 AM, and chose to go for another 'round' with Hiro.
Hiro, who on the other hand had seemingly unlimited sexual Stamina, agreed to her selfish request and kept going until she was exhausted again, when looking outside, it was morning already, as such they decided to finally go to sleep.
Hinata was still sleeping on the side with Hiro's right hand squished between her breasts.
Atleast they had bothered get a shower together before sleeping in the morning otherwise they would have been in a sticky mess.
Hiro slowly exited Hinata's grasp while not waking her up as he went outside after dressing up.
'Looks like it already started' Hiro thought, somehow, he could almost smell the tension in the air.
'Kankuro should have been left for dead by Sasori by now, team Kakashi should have also been deployed as aid to Suna by now' Hiro thought as he muttered "Its going to troublesome from now on"
Altough there was a chance Hiro may not be implicated at all in the upcoming events, the chance was infitesimally small.
He will try his level best to avoid getting involved, but there will be times when he would have to get inevitably involved.
And he was training only for those times, as a small amount could be the difference of life and death for him if he's careless, especially since he knew he didn't have plot armor.
He got his mind off the suna situation as he focused on his new form of training.
The Rokushiki techniques had been a great addition to his arsenal, almost doubling the damage he could output while making him more versatile and slippery in tight situations.
Another form of training he had been attempting were the Breathing styles.
In many Anime's, Breathing styles, patterns and techniques held great importance and almost always provided a great boost to physical attributes in more ways than one.
In Demon Slayer, it was depicted as a technique to unlock full potential and strength of human body to perform seemingly Superhuman feats and fight against demons
In first seasons of JoJo's Bizarre Adventures, Structured and controlled breathing could awaken the sun's energy in ones body, also know as the ripple breathing, 'Hamon' was the ancient technique that helped humans fight against Vampires and bloodborne creatures.
Even in Naruto, it was depicted that with a specific breathing style, one could gain power similar to the eight inner gates while still maintaining a smooth flow of chakra such that it could still be shape transformed.
Shira, a Taijutsu user of Suna had achieved this amazing feat, sadly he didn't have any more appearances and such, the true potential of this technique was unknown.
Hiro wanted to do just that.
He had analysed the eight inner gate technique of Guy and Lee for a long time, his conclusion was that even though the strength they gain via it is superior to Seven Heavens Breathing of Shira, they have a much more erratic flow of chakra in their body, which would become almost impossible to control if one goes beyond the third gate.
Since they are strong fist Taijutsu users, they have nothing to do with chakra Control, but same couldn't be said for Hiro.
His taijutsu mainly relied on his excellent, almost perfect control of his Chakra.
The eight inner gates technique won't be any useful to him, it would disturb his Chakra flow and make it difficult for him and would be detrimental to him.
On the other hand, Seven Heavens Breathing suited him perfectly.
Hiro, sat down, writing different things of the large paper, making a few diagrams of the human body too.
He continuously snipped different techniques he knew from his meta knowledge along with many jutsus of ninja world as he wrote down a prototype breathing technique.
It's premise was simple yet strong.
With the use of Yang chakra, Hiro would lace his lungs amd chest entirely in it while taking in huge breaths, expanding his chest unnaturally.
This was a standard technique used by Wind and fire users to temporarily increase their lung capacity by several folds to perform a specific jutsu.
Using that concept with each and every breath, he would be able to increase his air intake several times.
Using Yang chakra at the right moment, Hiro knew from his basic medical knowledge gained from Hinata that he would be able to completely absorb oxygen in the large volume of air he takes in.
Due to Ninja world physiology, this dozens of times of increase in oxygen intake stimulates the chakra coils immensely as they go into an overclocked mode, producing huge amounts of chakra in small amount of time.
All this extra chakra and extra oxygen stimulates the body and muscles in a similar way to the Guy's technique, but opposite to it, instead of forcing the gates to open, it gently opens them, this should allow him to still maintain control over the chakra.
Estimated benefits of using such technique would be that outside of a fight where this extra chakra is not used to open up the gates to immensify his physical prowess, all this extra chakra generated would help him recover his chakra 20-30 times faster than he already did.
This would mean that 2 hour time he usually takes to get his jonin level chakra reserves from 10% to a 100% could be reduced to 4-6 minutes.
While this technique looked hundred times better than the technique Guy and Lee use, it had an glaring flaw.
If somehow the breathing pattern is disturbed, he would suffer a small backlash as the gently opened gates will close down abruptly.
And since there were many factors that could easily disturb the breathing, Hiro would have to practice it for a long time before he can even think of using it in a battle.
Guy and Lee's technique could be used whenever they wanted as they used physical strength and willpower to force the gates open and could be used however long their body could support it.
Both techniques had their pro's and cons.
By the time he was finished with the prototype, It was already 4 PM, Hinata had resumed her own training by the backyard that had been turned into a training ground with many facilities by Hiro.
Hiro decided to give it a try as he asked Hinata to keep an eye out for any accidents that may happen.
## Hinata POV ##
I activated my Byakugan as Hiro kun asked me to as I watched him carefully.
He said that he wanted to try out some old technique of his clan that could increase his strength tremendously.
Hiro kun sat down on the grass as he took a meditating position.
Suddenly, his breathing started increasing as his chest started expanding unnaturally.
Through her Byakugan, it looked like he was using some wind justu, but all he did was inhale and exhale the air in a wierd pattern.
Hiro kun changed the weird pattern of breathing dozens of times in the last 15 minutes.
Suddenly, something odd happened, his Chakra coils started glowing immensely as a rich, much brighter blue color started spreading through his Chakra pathways.
"I'm getting closer, look out more carefully, it's a crucial stage" Hiro kun said in between his structured breaths as I nodded and intensified the byakugan.
Hiro kun changed his pattern subtly as is he was adjusting something, Suddenly something even more Bizarre happened, the intensified blue color of chakra started flowing incredibly fast.
I could feel his bloodflow increase by several times while the fast revolving chakra started seeping into his muscles.
'Is that... huh??'
'That was definitely the opening of the first inner gate!! I am sure of it!'
She had seen Lee and Guy sensei open their inner gates many times, it was definitely similar, but at the same time it looked fundamentally different than their techniques.
Suddenly, Hiro-kun's breathing became off as his Chakra started flowing erratically.
With wisps of chakra at my finger tips, I instantly released his Chakra points as all the extra chakra was released before it could do any harm.
"Hiro-kun, are you Allright????"
## 3rd POV ##
"Hiro-kun, are you Allright????"
Hiro listened to Hinata asking him as he looked towards her thankfully while his breathing returned to normal.
His clothes were drenched with sweat as he finally spoke.
"Thank you Hinata, if you didn't release those points, I would have suffered a terrible backlash" He said as he got up and took off his sweaty shirt and pant.
Hinata just shook her head at his thanks as she asked worriedly "What was that Hiro-kun??"
Hiro couldn't help but let out a sighing smile as he explained to Hinata.
"It is a special breathing technique Hinata, it was used by my clan to fastly recover their chakra, though it seems it can do many more times than it advertises.
You see, breathing is an important part of a living being, how we...."
Hiro continued giving a lecture out to Hinata on the importance and benefit of controlled breathing.
If possible he wanted to impart this breathing style to Hinata after he completes all the error correction work on this prototype.
Such a technique could become a life saver and would help her gain strength very fast, her strength was his strength, literally.
Plus, he was already in her debt by so much, his pride wanted to return that favor as soon as possible.
A/N : More stones the better, I'll be posting the extra chapter for 690 stones with tomorrow's release.