Tech Hero in Another World-Chapter 141: [140] Early action as a Superhero (12)

Kiriya finally collapsed onto the soft mattress of his bed after returning from Ren’s house. His body felt like it was carrying the weight of a hundred kilos—not just from exhaustion, but from the emotional burden still clinging tightly to his mind. He had just delivered the news to Ren’s family in person, and the result... well, exactly what you’d expect.

Over the phone, Ren’s mother’s voice had practically pierced his eardrums. "WHAT!? HE’S WHERE!? WHAT DID YOU SAY!? RENTARO!!" Her words were loud, frantic, and full of emotion—but underneath, it was a mother’s worry. No doubt, Ren would be facing one hell of a lecture when he got back.

Meanwhile, Ren’s father could be heard chuckling bitterly in the background. "Yeah... that kid’s always been stubborn. Just like when he was little," he said, half proud, half worried. And Ren’s little sister? She just pouted and shut herself in her room without saying a word. Ren may have been adopted, but that house loved him as if he were their own flesh and blood.

Kiriya stared up at the ceiling of his room. His breaths were heavy. Even though there were no physical wounds, his head felt full. His body trembled—not from fever, but from sheer mental fatigue. He hadn’t truly slept in nearly two days. And now, lying in his own bed at last... the world felt unfamiliar.

His father was gone. His birth mother had long left them, walking away with another man without so much as a glance back. Only his younger sister, Yuuki, remained. The one light left keeping Kiriya from falling into total darkness. Thankfully, their father had left them with a substantial inheritance—thanks in no small part to Ren’s help back then—ideas, research, and a few technical pointers that had helped skyrocket their business.

Of course, after his father died, certain family members tried to lay claim to that inheritance. Especially that two-faced aunt. But with Ren’s smarts—and some legal trickery from the genius boy—Kiriya managed to hold onto everything. All the assets, all the rights, became his. It had been a silent war, but no less exhausting.

And now, all of that felt far away. Irrelevant. Nothing felt more real than the fact that Fujisawa was gone.

That night at the dinner table, silence hung in the air. Kiriya stared into his rice bowl, not even touching his chopsticks. Then, a soft voice broke the stillness.

"Aniki... You don’t look okay," Yuuki said quietly. Her concern was clear in her tone, snapping Kiriya out of his daze.

"Huh?"

"Don’t ’huh’ me! I’m serious. Are you okay?" Yuuki asked again, her eyes sharp but gentle. Though they often bickered over trivial things—like her calling him "aniki," which she claimed sounded too macho compared to "onii-chan"—there was no teasing today. Today, Yuuki just wanted to know if her brother was alright.

Kiriya exhaled slowly. "I... I’m fine. Just need time, that’s all. But I’m more worried about Ren."

The moment his name came up, Yuuki’s eyes lit up. "Eeeeh!? Rentaro-niichan!?"

Kiriya let out a long sigh, annoyed for no real reason. "Wow, when do I ever get that kind of reaction? Always someone else first..."

Yuuki pouted. "What’s that supposed to mean, Aniki? You’re hiding something, aren’t you? Something happened to Rentaro-niichan, didn’t it?"

Kiriya paused, staring at the now-cooling food in front of him. He knew he couldn’t tell her the truth. How could he explain to his younger sister—who’d never even held a weapon—about combat armor, killer AIs, and the razor-thin line between life and death in Sudan? About a best friend who barely made it back... and about Fujisawa, who never did?

He forced a smile. "He’s... just busy, that’s all. But he’s going to be fine. Trust me."

Yuuki frowned, eyes searching his face. She didn’t believe him—but she chose not to press. Maybe because she understood that when her brother acted like this, it meant something serious was going on—something she wasn’t ready to hear.

She spooned her last bit of rice and sighed. Then muttered, "Hmph, I don’t get it... What does Rentaro-niichan even see in you, Aniki?"

Kiriya looked up quickly. "Hah? Are you saying we’re not compatible?"

Yuuki raised a brow. "You say that like you’re a couple. Don’t tell me... you’ve strayed from the path of righteousness?"

"WH-WHAT!? No way! I still like girls!" Kiriya nearly dropped his chopsticks.

Yuuki giggled, sipping her tea. "Well, that’s a relief... I mean, Rentaro-niichan is a genius, skilled, disciplined, and polite. It’d be a shame if he ended up with... someone like you."

"Hah!? Polite? Yuuki, you clearly don’t know him." Kiriya shook his head. "Yeah, I used to think he was a model student too, all prim and proper. But in reality? He’s mastered the art of being a jerk—granted, with elegance."

"Elegant style?" Yuuki raised an eyebrow.

Kiriya leaned back in his chair, staring at the ceiling. "Back in our first year of middle school, people used to talk behind our backs. I was ’the rich kid’ who supposedly got grades through connections, and he was ’the emotionless robot.’ They thought we didn’t hear them, but Ren... he heard everything."

"And then?" Yuuki leaned in, clearly interested.

"At first, he didn’t say a word. But one day, he walked right up to those kids. I thought he was gonna throw punches. But nope. He was sarcastic. Brutally sarcastic. His words were calm, but... sharp. He tore them apart, one by one, with logic and language so polite it couldn’t even be called rude. But the result?" Kiriya chuckled. "The entire class went silent. And no one ever talked about us again."

Yuuki’s eyes widened. "Ohh! So that’s the story! I heard rumors about that! They said there was this third-year guy who completely shut down the whole class with just words. That was Rentaro-oniichan?! That’s so cool!"

Kiriya rolled his eyes. "You call me ’Aniki,’ but every time his name comes up, you look like a fangirl meeting her idol."

Yuuki, just setting down her teacup, immediately pouted. "Hmph, well, he is cool. And he’s helped us a lot..." she muttered, cheeks starting to turn pink. She rubbed the bottom of the glass as if suddenly busy, but her flustered expression gave her away.

Seeing that, Kiriya could only let out a deep sigh. "Haah... Looks like you better act fast."

"Eh!? What do you mean!?" Yuuki snapped her head toward him, eyes wide with confusion, though her pitch was just a bit too high to hide the panic in her voice.

Kiriya crossed his arms, leaning back in his chair. "You know full well, even if some people don’t like him because of his cold attitude, there are still girls who secretly fall for the genius type. Even last Valentine’s, I saw it myself—some girls from other classes slipped love letters into Ren’s locker."

"WAWAWAWA!!" Yuuki nearly shot up from her seat. "Did Rentaro-niichan accept them!?" Her voice jumped several octaves, and her face was now as red as a boiled crab.

Kiriya stared at her flatly. "Of course not. You think he’s that easy to win over? He turned them all down. Said he’s not interested in youthful romance right now. He’s focused on more important things."

Yuuki slowly sat back down, visibly relieved. "Oh... I see..."

"But," Kiriya added with a slightly mischievous tone, "he also said that if, one day, he did become interested, he’d consider opening his heart... and choose just one."

Yuuki froze. Then slowly looked down, gently touching her own cheek. "Just one person... huh..."

Kiriya nodded slowly. "So, if you’re serious, you’d better make a move. ’Cause who knows—tomorrow he might catch the eye of someone new from the science club... or worse—the drama club."

"Eek! Don’t say the drama club! They’re all gorgeous!" Yuuki panicked, slumping over dramatically.

Kiriya let out a small laugh. That night, the dinner table—once weighed down by emotional fatigue—was slowly filled again with sound. The sound of family. And though the world outside was harsh and chaotic, this home still made space for small laughter... and maybe, just maybe, the spark of new hope.

---

Meanwhile, in the underground base, in a dim and silent lab, the only sounds were the hum of the air filtration system and the soft clink of glass against glass. Rentaro Takamura, hair disheveled and eyes refusing sleep, leaned over his lab table. His hands moved deftly—mixing compounds, measuring concentrations, and recording changes in reagent colors with cold precision, as if time itself had ceased to matter.

On the glowing monitor before him was a simulation of a human cell, complete with a modeled representation of Terminal Stage III—a rare and devastating medical condition with no known cure. The disease gradually ate away at the immune system from within, rendering it weaker with time, eventually rejecting nearly every form of conventional treatment.

One in a million cases. A life sentence delivered before death itself.

Fujisawa’s younger sister was one of them.

She’d been diagnosed at the age of ten. Seven years had passed since. By medical standards, she shouldn’t have survived this long. But she had—thanks to the sacrifice of the brother who now lived only in memory. And now, only Ren carried that will forward.

Ren had never met the girl in person. He had never heard her voice. But he knew what her smile meant to Fujisawa. And for Ren, that was enough. Because he knew all too well what it meant to lose family. The world had already made human lives fragile enough—he wouldn’t stand by and watch what remained of Fujisawa fade away.

His hands moved faster. The micro-reactor at the center of the lab processed complex biochemical components—work far beyond the scope of conventional medical technology. But Ren wasn’t an ordinary child. And the machines in his lab weren’t factory-made—they were all of his own design. These machines responded directly to his mind, carrying out genetic experiments and biochemical simulations at speeds no human system could replicate.

For thirty straight hours, without sleep, without leaving the room, Ren worked. Not a single sign of fatigue stopped him. His cheeks had sunken, dark circles rimmed his eyes—but the fire behind those eyes shone brighter than ever.

Finally, the liquid inside a small vial changed color—shifting into a silvery blue. Soft. Almost luminous. On the monitor, the graphs spiked—parameters reaching perfect thresholds.

Ren exhaled deeply and leaned back in his chair.

"...Done."

But done didn’t mean safe. The drug had never been tested. Never injected into a living human. The risks remained. But one thing Ren believed in with absolute certainty: if science was right, this could be a breakthrough that saved a life. At least one life. That girl’s life.

"Fujisawa-san... I can’t bring your brother back. But I’ll save your world," he whispered, clutching the vial tightly in his hand.

There was no time to waste. Kiriya had already found the hospital’s address the day before. And now that the formula was complete, Ren changed clothes and immediately set out for the hospital.

This 𝓬ontent is taken from f(r)eeweb(n)ovel.𝒄𝒐𝙢