A Ninjutsu Combining Four Types of Chakra

At that moment, Hideki held Lightning Release in his left hand and Water Release in his right.

Though both were the most basic ninjutsu, being able to use them would still make him a little genius if word got out.

But Hideki did not stop there.

What he wanted to do was far more than simultaneously cast two low-level ninjutsu for nearly a minute.

The education he had received did not permit such flashy but impractical tricks.

The small water ball in his left hand slid from the back of his hand into his palm.

Hideki's lips had turned slightly pale.

Though they were the two most basic ninjutsu, his age was what it was. Being able to use them at all was already impressive; he simply did not have enough chakra.

If only I could master the Eight Gates and Creation Rebirth. Without a bloodline, it really is hard to get by.

The thought suddenly popped into Hideki's mind.

The Eight Gates squeezed the body dry to provide far more chakra than usual.

Creation Rebirth, meanwhile, continuously repaired the body.

That way, chakra would flow endlessly—practically a perpetual-motion machine.

But Hideki still dismissed the thought. It was a little too self-destructive, after all.

And right now, he needed to focus completely!

His hands slowly moved closer together. The lightning in his right hand plunged directly into the water ball in his left.

The lightning did not vanish. Instead, bubbles began to form inside the water ball.

Hideki held his breath and focused, carefully protecting those bubbles. Gradually, the water ball in his left hand became increasingly distinct.

Gas was on top, liquid below.

In terms from school, the upper layer consisted of hydrogen and oxygen molecules produced when water molecules were ravaged by alternating current—commonly known as a hydrogen-oxygen mixture. It could explode.

Below that was water... still containing a certain amount of impurities.

2H2O = electrolysis = 2H2↑ + O2↑.

At that moment, Hideki suddenly remembered his third-year middle school chemistry teacher's gleaming bald head.

"Obito! Are you ready?!"

When the lightning in his right hand finally could no longer hold out and faded away,

the small water ball in Hideki's left hand had, under his precise control, shed the water that had not fully reacted due to insufficient chakra, along with the impurities, leaving behind a single bubble!

Hideki crouched halfway down, with half his body poised to run. His arm stretched out long, giving him the look of someone about to light a firecracker.

But he would not be the one lighting it. Obito would!

"Hideki!"

"Let's begin!"

"Three! Two! One! Run!"

After finishing the countdown, Obito violently hurled out a burning cotton swab.

This time, his throw was dead on. It landed right at the center of the bubble just as Hideki took off running!

The next second—

BOOM!!!!!!

The explosion was several times louder than a firecracker. Hideki had run in advance and covered his head, yet his ears still rang from the blast!

But he could not stop the corners of his mouth from rising.

"It worked... it worked, Obito!"

"Holy shit! It worked, Hideki! You're incredible, Hideki!!!"

The two boys shouted excitedly at each other.

They definitely would not lose tomorrow's arranged fight!

That night,

Hideki returned home and rested properly first.

Once his chakra had mostly recovered, he ate a meal as well, restoring his strength.

Early the next morning, Hideki got up and began refining chakra.

It was not until noon, as the time for the arranged fight drew closer and closer, that Hideki began repeating yesterday's process.

Only this time, there was also a small drink bottle beside him.

"A hydrogen-oxygen explosion needs an open flame, and the space needs to be compressed... Four hundred milliliters should be enough."

Hideki calculated.

Though he had been a humanities student, he had usually managed to pass chemistry in middle school.

He was determined to win today's fight.

Come to think of it, it was a rather sad story.

People in the Shinobi World had physiques stronger than those in his previous life.

Hideki felt that even though he had transmigrated bodily, he might not necessarily be able to beat those brats.

But he was not worried about the consequences.

His predecessor had been beaten badly enough for him to transmigrate into this body. Why should he hold back?

Besides... this amount probably was not even as powerful as a low-level Fire Release.

If Obito had not been so hopeless, practicing the Great Fireball for so long without getting anywhere, the two of them would not have had to suffer like this.

But if anyone thought he was doing all this merely for an arranged fight,

they would be completely wrong.

Using Lightning Release to electrolyze Water Release, then igniting the resulting hydrogen with Fire Release—

in a sense, he was creating a ninjutsu!

And it was an extremely complex composite ninjutsu at that.

Water Release plus Lightning Release, then Fire Release; the hydrogen could even be controlled with Wind Release.

Two chakra natures were called a Kekkei Genkai, while three chakra natures were called a Kekkei Tōta.

So here was the question.

What was four types of chakra called?

Hideki was not some childish little brat who spent all day playing with firecrackers.

This was Hydrogen Release!

He was doing something big!

Come to think of it, Hideki had always felt that his talent should be fairly decent.

His parents had left him a small wooden house, along with two beginner-level ninjutsu.

His Lightning and Water chakra natures had probably been inherited from them as well.

But he had not relied on anyone for today's feat.

He had figured it all out bit by bit, researched it bit by bit.

Perhaps it was thanks to his powerful soul that his chakra control was especially delicate.

The only flaw was that he had far too little chakra.

If he had started out as a member of the Senju Clan, what he would be preparing for those brats tomorrow would not be a mere little plastic bottle of hydrogen gas...

"Whew... This will have to do."

He carefully filled the small plastic bottle with the hard-won Hydrogen Release, then hurriedly sealed it.

Making it was easy; preserving it was difficult.

He also had to prevent accidental leaks or friction during the process, which could ruin everything before he even got started.

Knock, knock, knock—!

At that moment, there was a knock on the door, followed closely by Obito's voice.

"Hideki, are you ready?! Those guys have already set out!"

"I'm coming, I'm coming!"

Hideki immediately put away the little bottle, hid it in his clothes, put on his shoes, and dashed out.

"Did you bring it?"

"Of course!" Obito took a bottle cap from his pocket.

Its size and dimensions were exactly the same as the cap on the bottle in Hideki's clothes, except it had a small hole in the middle.

Do not underestimate that little hole. It was the key—the airtight precision of a humanities student, and the stubborn defiance of two boys who were always getting beaten before their comeback.

Obito took out a thumb-sized firecracker from his pocket as well. It was just the right size to fit into that hole.

"Put it in now, or wait until later?"

"Later. We don't want it leaking out the side," Hideki said.

The two exchanged smiles.

Then they rushed straight toward the meeting place!

The place for the arranged fight was a small park.

No one came around lunchtime. It was busiest in the evening, and at night, occasionally, sounds desperately suppressed could be heard from a corner of the park.

Hideki remembered that Team 7 from three consecutive generations seemed to have competed for Bells in parks like this.

He did not know whether it was the same place.

The two of them were not early.

Several times their number of brats had gathered here long ago, bolstered by their absolute advantage and confidence.

Their clothing all looked very similar, but not because they were professionals. It was because they all came from the same clan.

Konoha's Uchiha Clan.

The leader looked to be around ten years old. He was tall, with spiky hair similar to Obito's, only longer.

When they saw the two arrive, with one of them furtively keeping a hand inside his clothes, several Uchiha brats immediately began mocking them.

"Well, look at that! You actually dared to come?"

"Obito, I thought a piece of trash like you would bring your grandma along. You've got some nerve, huh?"

Come to think of it, Obito's childhood had been rather miserable.

He only had a grandmother at home. He was the dead last at school, and he was not well regarded within the clan either.

That alone would have been nothing, but a few months ago, after getting beaten up while protecting Hideki, Obito had gained another title among the children besides "trash": "the shame of the Uchiha."

It was given to him by the guy standing before them, Uchiha Beiying.

At that moment, enemies met with eyes blazing red.

Yet Obito appeared exceptionally calm.

He silently handed the firecracker from his pocket to Hideki.

A moment later, Hideki handed the small bottle, its opening plugged with the firecracker, back to Obito.

"Let's end this, Obito!"