Precise Measurement

It could be trained!

Akaseki discovered it with delighted surprise...

The emotional stimulation he experienced during "Immersion" could affect changes in chakra. As long as he opened his eyes in time, he could put that effect into practice!

With that in mind, Akaseki began stopping at each emotional peak to activate his Sharingan. Following Fugaku's instructions, he visualized Fire Release Chakra, using emotional stimulation to affect his Dojutsu Power and his Dojutsu Power to alter his chakra...

An hour passed. Akaseki felt... the results were even better than he'd imagined!

This kind of technique was supposed to depend on years of accumulation. Dojutsu Power wouldn't immediately change the nature or form of chakra.

Generally speaking, no method of training chakra nature or altering its form could show quick results, much less lead to sudden enlightenment. The only difference was that geniuses progressed faster and ordinary people progressed more slowly.

However...

That one hour had been 120 hours for Akaseki!

And during those 120 hours, Immersion had kept him steeped in intense emotional outbursts. Every few minutes brought a new emotional peak...

Even if each instance of these artificially induced emotions had only a small effect, it all added up over time.

Moreover, although his consciousness had experienced a longer stretch of time, his body—and especially his Sharingan—had only endured an hour. So Akaseki had managed to persevere. He'd stimulated his eyes for only about ten minutes in total, and with fine control, he didn't need to fully activate them. A little stimulation was enough, and it didn't consume much Dojutsu Power.

After just one hour, Akaseki could already feel that his Fire Release Ninjutsu burned a little hotter and was a little harder to extinguish...

That was right. In terms of the types of stimulation, the hour had been "seventy percent Anger, thirty percent Sorrow." As for "Joy" and "Happiness," they hardly counted.

The only reason there had been any "Sorrow" was that his hypothalamus had been forcibly taken over. Otherwise, Akaseki would have felt nothing but "Anger."

With that, Akaseki had gained another training regimen: while watching short dramas in Immersion, he could activate his Sharingan whenever his emotions surged, stimulating changes in his chakra!

Akaseki figured that even the most talented Uchiha could at most get better results from each instance of stimulation. None could match his efficiency.

While "watching dramas" that evening, Akaseki received a new reward...

[A Prosperity Realm Physical Examination Device. Just one drop of blood is needed to check your entire body. Results in sixty seconds. Know your health early...]

"A physical examination device? What the heck is this?" Akaseki was wondering when he felt a slight tug at his brow. A drop of blood had already been taken from him. That was right—it had automatically gotten his consent again while he wasn't paying attention.

Akaseki: ...

Still, he'd been planning to test it anyway.

[Testing... Abnormal genes detected... Revising test items... Testing... Revising test items...]

Akaseki was puzzled. Wasn't this supposed to take only sixty seconds?

The results finally came after two or three times that long.

[Examination Results:

Fire Release Chakra (awakened, 0.43%): Swift Flame (0.01%), Scorching Heat (1.12%), Incineration (0.88%), Overspread Burning (0.20%), unknown, unknown.

Earth Style Chakra (awakened, 0%): unknown, unknown, unknown, unknown, unknown, unknown.

Lightning Style Chakra (awakened, 0%): unknown, unknown, unknown, unknown, unknown, unknown.

Wind Release Chakra (not awakened).

Water Style Chakra (not awakened).

Yang Release Chakra (not awakened).

Yin Release Chakra (awakened, 0%).]

Akaseki: ???

What was this supposed to be?

Was this a physical examination?

Why was it checking changes in chakra?

And... what did Swift Flame, Scorching Heat, and Incineration mean?

At first, Akaseki thought the results made no sense. But then he remembered the pleasant surprise the device had given him earlier, calmed down, and considered them carefully without letting his biases get in the way. A new thought struck him!

"Wait... judging by what's 'awakened,' this does match my current state: Fire, Earth, Lightning, and the Yin that awakened naturally when I opened my eyes... And aside from Fire Release Chakra, everything else is 'unknown.' Could it be..."

Akaseki immediately realized that the difference in his Fire Release Chakra came from the four emotions he'd just used to stimulate its changes!

As soon as the thought occurred to him, Akaseki understood. [Swift Flame] referred to the speed at which flames spread, [Scorching Heat] to their temperature, [Incineration] to how difficult they were to put out, and [Overspread Burning] to the area covered by the flames. They corresponded to the changes in Fire Release Chakra brought about by stimulation from the four emotions of "Joy, Anger, Sorrow, and Happiness."

The percentages also showed the differences between the four...

Swift Flame was the lowest, Overspread Burning came next, Scorching Heat was the highest, and Incineration was second-highest.

That matched Akaseki's earlier experience...

Who could possibly feel "Happiness" while watching this damn Family Happiness? Even Akaseki couldn't figure out where that 0.01% of Joy had come from... Maybe he'd felt Joy while "laughing at himself," thinking the protagonist deserved what he got?

As for "Happiness," he occasionally managed a laugh. It was probably that feeling of "laughing in anger."

"Anger" had been the most common emotion, with "Sorrow" close behind. For Akaseki, the former mostly came from emotions he'd deliberately stirred up himself, while the latter was more often driven by the Immersion System...

Once he understood this, Akaseki saw that the Immersion System seemed to divide changes in chakra into six categories, rather than simply "changes in nature" and "changes in form."

As for the percentage after [Fire Release Chakra (awakened)], Akaseki did the math and realized it was the average of the other six values, like an overall progress indicator.

That explained why the categories for his other chakra types were still unknown: they hadn't changed yet!

Until now, Akaseki had only used emotions to stimulate his Fire Release Chakra. The Uchiha Clan hadn't documented training for other chakra types in much detail, so Akaseki would have to figure out how to stimulate them and what changes corresponded to each kind.

Also, there were still two unknown changes under Fire Release. That suggested there were other emotions besides "Joy, Anger, Sorrow, and Happiness" that could stimulate changes in chakra. They were probably just rare, and the Uchiha Clan hadn't identified them.

Akaseki could make a rough guess at what the two remaining Fire Release changes were: "Adhesion" and "Explosion." The former would make Fire Release Chakra more likely to stick to a target and let it cling to ninja tools. The latter would make it "explode," increasing its impact instead of injuring people with heat.

Fire Style: Phoenix Sage Flower Nail Crimson and Fire Style: Ash Pile Burning were examples of these two changes. The former added flames to shuriken, while the latter caused an explosion. Both were ninjutsu unlike ordinary Fire Release techniques.

"These percentages... Could this thing really measure them that precisely? Or is it just making them up?" Akaseki was still doubtful.

But then he thought about how miraculous the system had been so far. Perhaps... it was telling the truth?

On the surface, the Physical Examination Device merely let Akaseki check his condition. It only observed; it didn't change anything.

But if it could really be this precise, then the value of simply "checking" was already immeasurable—perhaps even greater than that of the Eye Protection Device or Massage Device!

As Fugaku had said, training to change chakra was a process of slow, day-by-day accumulation, building up before reaping the rewards. It wasn't like learning a new ninjutsu, where once you knew it, you knew it...

In other words, before the payoff, the positive feedback from all that "accumulation" was small. It was easy to start thinking things like "This doesn't seem to be doing anything" or "Am I training wrong?" and then slack off and fail to persevere.

But if he could see his progress precisely, that alone would be a tremendous encouragement...

Just like now. Akaseki immediately threw himself back into the plot, full of enthusiasm, and kept training. Whenever his Dojutsu Power recovered, he practiced ninjutsu; whenever his stamina recovered, he practiced Taijutsu... He kept at it all night.