I Play Ninjutsu in Jujutsu Kaisen! Chapter 21

But that's just how battlefields are—real martial arts don't care about flashy moves, only how fast you can put someone down.

Cursed spirits might not have those weaknesses, but a jujutsu sorcerer's enemies aren't just curses born from curses—they're also humans who are sorcerers themselves.

Different factions meant different beliefs, and that bred conflicts of interest. Conflicts naturally led to fighting.

Anyway, the messier the better—more skills never hurt anyone. As long as he could copy it with his Sharingan, Natsu Hiraku took it all without discrimination.

Time trickled by. Ido Shuichi was already sweating, every punch laced with heavy beads of perspiration. Even as his breathing grew ragged, the fists he threw stayed steady.

My eyes are so tired...

Natsu Hiraku wasn't having a great time either. The sunglasses blocked part of his vision, making the Sharingan harder to use than usual. And that wasn't the worst of it—his brain needed to keep patching things together.

This was what they called pain and pleasure mixed together.

Learning new knowledge excited his brain, but the heavy burden was wearing him down.

It was so bad he felt nauseous. The world in front of him seemed to spin. So sick... my eyes hurt... I can't keep learning.

Without him noticing, red blood trickled from beneath the sunglasses down his flushed face. Ido Shuichi caught the abnormality and stopped his movements.

Blood slid down Natsu Hiraku's face and dripped onto the floor. Ido Shuichi shouted in surprise:

"You okay!?"

"I'm fine..."

Natsu Hiraku deactivated his Sharingan, panting heavily as he lowered his head. The sunglasses fell to the ground, slick with sweat, and the blood seeping from the corners of his eyes mixed with his sweat to stain his entire face red.

"Fine my ass—what's wrong with your eyes?"

Ido Shuichi was a little panicked himself. It was the first time he'd ever seen someone make their eyes bleed from learning martial arts. For a moment, he had no idea what to do.

"Master Shuichi, grab me a towel. I'll be fine after I rest a bit."

"Oh—okay, hang on. Don't die on me. I'll call an ambulance."

Ido Shuichi snapped out of it, quickly pulled out his phone from his pocket, and ran to the corner to grab the towel they used to wipe off sweat after training. Even though it was for sweat, they always washed it after use, so he wasn't worried about infecting the wound.

"No, really, it's fine. This happens all the time. No need to call an ambulance."

Natsu Hiraku quickly stopped him. He'd run into this situation right after he first transmigrated—back then, it was probably because he'd just awakened and overused his eyes. Same deal now.

"..."

"You sure?"

Ido Shuichi hesitated, his right hand still hovering over the call button. After all, Natsu Hiraku didn't seem like the type to mess around with his own health—the kid was way too slippery for that.

The more that type of person, the more they valued their own life above all else.

"Really, I'm sure. Just give me the towel. I've already memorized everything you showed me. Once I rest a bit, we can spar. I just can't learn any more right now."

"You learned it?"

Ido Shuichi handed him the towel, looking at Natsu Hiraku with half-belief. If anyone else said they could remember it all after one look, he wouldn't buy it—every move and stance was intricate, requiring adaptability on the fly.

But this kid... maybe. Too bizarre to rule out.

Wiping the sweat off his face, Natsu Hiraku tried to open his aching eyes, but failed every time. For some reason, he could feel that these eyes were saturated.

Not the kind of saturation from filling them with cursed energy—it was more like the eyes themselves had hit their limit. He didn't know what would happen if he broke past that limit, but he could feel it. Maybe next time he pushed them to the edge, something would happen. Or maybe nothing would happen, and he'd just go blind.

After all, normal eyes couldn't handle this much blood loss. The Sharingan might break too.

Gotta be careful.

If he went blind, he'd end up like Gojo Satoru—him with his black blindfold, and Natsu Hiraku with a white one. Gojo could see through his, and Natsu Hiraku would navigate by sound. The underworld would call them:

The Black and White Duo!

After all, Gojo had white hair and a black blindfold, while he had black hair and a white one.

Perfectly reasonable!

Even though he couldn't open his eyes for now, his body could still move. Under Ido Shuichi's curious gaze, Natsu Hiraku bent down, fumbled around on the floor, picked up the fallen sunglasses, set them on the table, then slowly stood and took a few steps forward.

Then, to Ido Shuichi's shocked eyes, Natsu Hiraku started moving his body. The punches he threw were clearly weak, but his form was spot-on.

The lack of power made sense—he'd looked so frail just moments ago. The fact that he could even move was impressive enough, let alone the perfect posture, as if it had been copied.

Did he really learn everything?

As time passed, Ido Shuichi grew more and more incredulous. From start to finish, it was like copy-paste—every move displayed to perfection, and his body was growing stronger by the second.

He couldn't help but admire the kid's freakishness. Eyes bleeding and he called it normal. Body weak and he still pushed himself to lock in the memories. Why would someone so slick work this hard?

It seemed that even after years on the battlefield, he couldn't fathom that unique mindset. All he could do now was teach him well. If his own Master had called him a weirdo back in the day, then this kid was a monster.

A genuine... monster.

The figure in his mind moved rapidly through the motions, and Natsu Hiraku mimicked them like tracing a gourd. He firmly believed that only by growing strong could he live in peace, and only by grinding harder than everyone else could he develop fast—time waited for no one.

His eyes felt a lot better, but he still couldn't open them. At least they didn't hurt as much as before.

The cursed energy that had drained from his body was slowly recovering, fueled by the negative emotion of pain. The amount was small, but enough.

His weakened body gradually regained strength under the boost of cursed energy. The techniques in his memory were dwindling. Complicated as they were, they boiled down to three principles: stability, precision, and ruthlessness.

But learning those techniques gives you more options to adapt—you can't do without either.

Having moves means you can't afford to be soft-hearted; being ruthless means nothing without the moves to back it up.

Even if you master a full set of martial skills, on a battlefield that shifts in an instant, one moment of hesitation can get you killed. A cruel heart without training just leads to death.

Of course, that excludes those quick to switch sides—provided you're useful enough.

As the final technique settled in his mind, Natsu Hiraku stopped. He took a deep breath, gently opened his eyes, and looked at the familiar world before him.

For some reason, the fear that had lurked in his heart had now dissipated. He dreaded losing the light, losing these eyes—if that happened, all his efforts would seem so mediocre.

A world without light was desolate, like walking through an abyss of terror, watched by those ever-present curses. That feeling made Natsu Hiraku deeply uneasy.

"Are your eyes really fine?"

Ido Shuichi stared hard at Natsu Hiraku's eyes. After all that bleeding just now, it would be a lie to say he had no concerns.

"Sorry to worry you, Master Shuichi. My eyes are fine. Want to spar a bit?" Natsu Hiraku gave a faint smile, though it made his face look pale, and the exhaustion in his eyes couldn't be hidden. Still, he acted like nothing had happened.

This brat—does he think his body's made of iron?

Ido Shuichi frowned, turned toward the training post, and waved him off. "No sparring. If you fail tomorrow's test, I won't teach you anymore. Get the hell back to sleep."

"But..."

Natsu Hiraku pursed his lips. He wanted to test his current strength more deeply, but his master clearly saw he was already exhausted and didn't want to fight.

He had no choice. "Yeah, I get it, Master Shuichi."

"Then go. Don't bother my training."

Ido Shuichi shouted and started pounding the training post. The "thud thud thud" echoed through the room. Natsu Hiraku glanced over and left.

Though he'd learned a lot tonight, he still felt a bit regretful. Training without real combat was hollow—combat was the only true measure of strength and the fastest path to growth.

If conditions allowed, Natsu Hiraku could even go without eating or drinking for a whole day of learning. As long as his eyes held out, either he or his teacher would have to drop dead.

But being sent away was unavoidable. Today was what it was.

"Ring, ring, ring..."

The bedside alarm went off. Natsu Hiraku slowly opened his eyes, turned it off, and sat up. He looked at the faint light seeping through the curtain gaps, a hint of confusion in his gaze.

Familiar ringtone, but this doesn't seem to be my room...

"Slap!"

The sudden sound echoed through the room. Natsu Hiraku covered his face and muttered, "Enough already. Got so into training I forgot I'm not at the academy anymore. I'm on a protection mission."

After slapping himself awake, he grabbed the backpack from the corner. It held not just his Cursed Tool, but also his clothes.

He changed, washed up quickly, and headed out. It was about 5:40—prime time for a morning run. Of course, he could also pick up a thing or two from the other guards. No matter how skilled they were, everyone had their own understanding of martial arts, and he could learn from that.

Only this way could he ensure he was getting stronger every moment. That was what it meant to never refuse a chance to improve.

Facing this powerful curse, Natsu Hiraku felt this was his only option. A permanent boost of 100 cursed energy was a qualitative change for him—it let him cast one more Great Fireball Technique and sustain his Sharingan longer.

As for the 15 points, forget it. If he gave up on this mission, it would be an unforgivable sin, a wasted life!

He pushed open the villa door and said to the two men standing guard, "Morning."

They turned, saw it was Vice-Captain Natsu Hiraku, and saluted. "Good morning, Vice-Captain Hiraku."

"Good. By the way, where's Captain Shuichi?"

"The captain's on patrol. Vice-Captain, are you looking to spar with him?"

The other chimed in, "Vice-Captain, what did you learn from the captain last night? Can't you teach us a bit?"

"Want to learn?"

Natsu Hiraku asked with interest.

"Of course."

Both of them craved even a sliver of the captain's martial arts. Here, rank was determined by strength. If they learned even a little, they might be able to challenge Murata Shoichi—after all, he was still Vice-Captain after Natsu Hiraku left.

That Vice-Captain position was the highest honor in the squad. As for why not captain... they couldn't beat him. He was too fierce, felt like he wasn't even from the same world.

"No."

Natsu Hiraku waved and walked off, leaving the two looking disappointed.

As if. If you want to learn, apply for a one-on-one and beat me. If you can win, no one will envy you for learning as much as you want—because you earned it!

Might makes right—that rule never changes. Whether in cultivation or a futuristic city, only the strong earn respect.

He wasn't some great philanthropist. If their own captain wouldn't teach them, why would they expect a temporary Vice-Captain to?

He hadn't taken two steps when he ran into Ido Shuichi on patrol. He quickly stepped up and said, "Good morning, Master Shuichi."

"Up pretty early. Your eyes really recovered?"

Ido Shuichi looked slightly surprised to see Natsu Hiraku awake so early. Normally, recovering from an injury consumed a lot of energy, and sleep would be deeper than usual—some people couldn't even be woken by thunder. Yet this kid was up this early. Was his body really made of iron?

"Sorry to worry you, Master. It's nothing serious." Natsu Hiraku continued politely, "I'll be at yesterday's training spot at eight tonight. Please don't go easy on me in our spar."

"Fine. I'll be waiting at eight. Don't think just because you've learned a few tricks that I've got nothing else to throw at you. Don't get too cocky—you've still got a long road ahead."

Ido Shuichi looked proud at that moment. After thinking it over all night, he had come to terms with it—since the kid called him Master, he naturally had to treat him as a disciple. Having such a talented disciple was certainly something to be proud of.

No matter what he said out loud, if he had learned that fast back in the day, he wouldn't just be proud—he'd have dared to piss on his own Master's head.

"Got it. I'll go find two sparring partners, then. Master, you keep training."

Natsu Hiraku nodded to show he understood, then waved and left directly. He was going to find those two gatekeepers from yesterday—he'd said they'd train together, and he couldn't go back on his word.

Even if breaking his promise wouldn't matter much, it would still weigh on his conscience a little. Besides, he could also observe their martial skills. Two birds with one stone—why not?

The two men stood at the main gate.

"You think Vice-Captain Hiraku will actually train with us?"

"No idea. But as Vice-Captain, he probably wouldn't go back on his word, right? If he teaches us, we'll soar to the top!"

"That sounds nice, but he's the Vice-Captain. That rank is earned through strength alone. It'd be a blessing if he even spars with a couple of weaklings like us—don't expect actual teaching."

Go-in Roku shot a contemptuous glance at Ryusui Ruo Bing beside him, his expression practically saying: 'Stop dreaming. This is our lot.'

Ryusui Ruo Bing shrugged, looking unconcerned. "Maybe the Vice-Captain's kind-hearted. Don't crush your own dreams and drag me down with you."

"You looking for a fight?"

"Bring it on! We're both stuck as gatekeepers anyway, pretty much equals. Think I'm scared of you?"

"..."

Go-in Roku was at a loss for words. Their strength really was about the same. After a long pause, he finally spat out: "Damn it."