Naruto: Reborn as Sakura with Manyuu Chifusa Template Chapter 271: The Seven Heavens Breathing Method!

"Thank you," said Shira.

"Are… are you talking to ?" asked Sakura, turning away from the spectator stands to face her interlocutor.

Shira was the eponymous leader of Team Shira— her opponents in the match that was just about to begin. He was a tall, musclebound bloke with steely grey hair and two duelling scars: one on his left cheek, and another one across his neck. He had two kunoichi for teammates: Sen, a tall, blonde kunoichi who wore her afro swept up into a ponytail, and Yo, a tiny girl with rosy cheeks, twintails, and large, owl-like eyes.

"Yes," said Shira curtly, swallowing his distaste for the woman before him as he offered a slight bow. "Lord Gaara told it was because of you that he changed his violent ways, and for that, I am grateful."

"Is that so," said Sakura disinterestedly.

Shira's expression darkened ever so slightly.

Curious about the woman who had had such an impact on the Kazekage, Shira had followed Sakura's matches closely and taken special care to collect as much information on her as he could from his comrades in the Hidden Sand, but her general attitude was disappointing him.

It was obvious that the large-chested girl standing before him didn't take him or his teammates seriously, and that she didn't seem particularly interested in fighting them either. Even now, she'd barely given him a second glance when he'd spoken to her. Was she looking down on him because she had learned that he could only use Taijutsu, he wondered?

If so, then he would teach her the true aning of martial arts…

"Who will you send out to fight first?" asked Baki, eyeing the two teams in turn. "Though, do keep in mind that under tournant rules, neither Akimichi Chōji nor Sen may lead, as they've already done so in the previous match."

"I'll go," said Sakura rather grumpily. "The sooner we get this over with, the better."

"I'll fight," said Shira, maintaining a neutral expression.

Unfortunately for Shira, he'd caught Sakura at a rather bad ti. Under normal circumstances, she was nice and even-tempered, but when she was cross, she could be thoroughly unpleasant. Over the past two years and a half, she'd mostly adjusted to the wild mood swings that ca with her newly awakened Uchiha bloodline, but her powerful emotions still had a habit of getting away from her from ti to ti.

Uchiha blood was just like a certain Super Soldier Serum from Arican comic books— it amplified both the good and the bad.

For example, upon finding themselves in an Uchiha clan mber's body, a Chinese ti-traveller might beco even more bloodthirsty and avaricious for benefits, a Western reincarnator might beco even cringier than they initially were, and a Japanese transmigrator might beco even more of a degenerate gooner!

(I'm generalising, of course— there exist reasonable Chinese protagonists, charismatic Western characters that don't make you feel like groaning out loud, and NNN-following Japanese MCs that don't go around purchasing busty slaves for their harem.)

Baki, Chōji, Ino, Sen, and Yo retreated to a safe distance, leaving Sakura and Shira in the centre of the arena. Shira took up a fighting stance, but Sakura maintained a sort of Fool's guard— that is, she remained planted right there on the spot, with her arms hanging casually at her sides.

"BEGIN!" shouted Baki.

Shira imdiately lowered his gaze, careful not to et Sakura's eyes. According to the information he'd gathered from his comrades, she possessed a two-tomoe Sharingan. Her Dōjutsu might have pretty much gone extinct from the Shinobi World, but the Sand's war archives still held records of the Uchiha, and they all said the sa thing: to look an Uchiha in the eye was as good as signing your own death warrant.

For so reason, his opponent Uchiha Sakura hadn't used her Genjutsu so far in the third exam— perhaps she favoured using flashier Ninjutsu to impress the judges for a better shot at a promotion, or perhaps she was simply looking down on her opponents— but either way, Shira had no intention of underestimating her.

Shira took in a deep breath, filling his lungs with air. He was going all out from the start!

"Seven Heavens Breathing thod: First Activation!"

…

It must be known that human lungs are an extrely inefficient organ.

When a person takes a breath, stale air mixes with fresh air, diluting the oxygen concentration in the lungs before it can even reach the bloodstream— and as if that weren't inefficient enough, the concentration gradient at the exchange point is utterly dreadful as well.

At the blood-air barrier, the lungs' alveoli perform gaseous exchanges with the capillaries via passive diffusion (CO2 cos out of the blood and O2 goes in), because nature abhors a vacuum. O2 will move from areas of high concentration (the alveoli) to areas of low concentration (used blood) … but the problem is that between breaths, the air just sits there in the alveoli, while the blood flows in a set direction, which ans that O2 levels at the two exchange points will naturally attain an equilibrium at 50%/50%... at best. At this point, there is no more concentration gradient.

That's a 50% loss, when you could be breathing half as much for the sa result! Such a waste of effort!

However, by using his Seven Heavens Breathing thod, Shira could achieve near perfect efficiency in the gaseous exchanges taking place in his lungs. By using chakra to force the air in his lungs to move in a fixed, one-way flow, he ensured that there was always a concentration gradient— that is, there was never a mont in which oxygen-rich air couldn't find low-oxygen blood to perform an exchange with. What's more, he could ensure that old, stale air could remain separate from new, fresh air, further increasing his efficiency!

Unfortunately, there is such a thing as too much of a good thing: naly, oxygen toxicity.

As the na suggests, oxidation, a destructive process in which electrons are lost, is pretty much oxygen's fault (most of the ti, since it's the most common oxidising agent). Oxygen might be necessary for us to live, but too much of it can kill…

Flas and rusting tal are but two very visual examples of oxidation, but it can also happen to one's tissues: causing cellular damage that can lead to cancer (which is why antioxidant is such a popular buzzword in yogurt advertisents).

To avoid hyperoxia (whose symptoms include: breathing difficulties; chest pain; light-headedness; disorientation; cell collapse in the lungs, nervous system, and eyes; seizures, retinal detachnt, death, etc.), Shira has no choice but to tabolise his oxygen as quickly as possible by overclocking his bodily processes… which inevitably causes tissue damage as well. Even so, the payoff is worth the price: The Seven Heavens Breathing thod also grants power equal to the release of the Eight Inner Gates!