Inside the laboratory.
Bulma first handed Uchiha Hikari a pair of oddly styled goggles and gloves, putting on a set herself. Then she pulled out a device that looked like a flashlight. When she flicked the switch, a narrow, blade-like beam of pale purple light shot out, extending two or three meters before slightly dispersing.
"This is a laser sword. The beam's made up of ultraviolet, infrared… even gamma and X-rays. Press the button, and it releases them as a high-energy beam, shaped into a sword by a magnetic field. You can adjust the light's intensity here…"
"But this beam can harm human skin, so you need the goggles and gloves. And be careful not to hit anyone with it… Though, knowing you, Hikari-chan, you'll handle it just fine."
"Hm…"
Hikari watched as Bulma demonstrated several laser swords, mulling it over for a moment. "Did you pay the Jedi Order for the copyright?"
"Huh?"
Bulma gave her a puzzled look, but Hikari didn't elaborate. She stepped forward, took one of the laser swords, and gave it a few test swings. "These beams… they don't have a physical form?"
"Of course not! It's just light, how could it be solid?" Bulma's tone was matter-of-fact.
Fair enough.
Whether it's lasers or radiation, they're all electromagnetic waves at their core. When they collide, they'd pass right through each other, not clash like fluorescent tubes in a dramatic showdown.
"But what you're talking about *is* theoretically possible," Bulma said, rubbing her chin thoughtfully. "If we swapped the laser for ultra-high-density plasma and used a stronger magnetic field to shape it, it could cut like a real blade… The problem is, plasma particles lose energy when they collide with neutral air. We'd need to solve that to keep the sword stable for long…"
As Hikari stood there, utterly lost in the technobabble, Bulma dropped the topic and moved to the next workbench.
"And this!"
"This is a UV-protective suit. It's a bit heavier than a normal jacket. When you press this switch, it emits a blinding light like the sun, creating a 360-degree, no-blind-spot illumination around you, bright as day. In open areas with no trees or buildings, it can cover a 200-meter radius. The energy lasts about two to three hours…"
"…Solar Flare, huh?"
Hikari couldn't help but quip.
Bulma kept going:
"But after hearing you and Tanjiro talk last time, I wasn't sure if this would actually work. So, just to be safe, I came up with something new. Ta-da! This is it!"
"I call it the 'Mini Bracelet.' Wear it on your wrist, press this button, and your whole body shrinks to the size of a finger. Then you can hide in someone's pocket."
To demonstrate, Bulma pressed the button, and her body visibly shrank to just a few centimeters tall. She stood at Hikari's feet, waving up at her.
"…Wow."
Hikari had to admit she didn't understand science.
In her mind, shrinking a person to the size of a finger in an instant was way crazier than laser swords or plasma. But Bulma's tone made it sound like this was easier to develop than the other two… Considering the *Dragon Ball* world had things like Capsule Corp's universal capsules, maybe the principle behind size-shifting wasn't *that* complicated.
Still…
(This tech tree is *wildly* skewed…)
Even if you counted from the last time they collected the Dragon Balls, Bulma had, at most, two months to work on these inventions—while still attending school. Her efficiency was downright absurd.
"Got any other new gadgets, Dora-Bulma?"
Hikari blinked, looking at Bulma expectantly.
Under her gaze, Bulma scratched her head, a bit embarrassed. "That's it for now… Well, there's one more project I'm tweaking—a firearm version of the laser sword, tentatively called the 'High-Energy Particle Gun.' But it's just a prototype with a ton of technical issues, so I'm not showing it to you this time, Hikari-chan."
"…"
She actually had more?
Hikari was a little speechless.
She'd thought a 16-year-old Bulma, genius or not, would have limits. In the original story, her inventions like spaceships and time machines came nearly a decade later. But now… Hikari had clearly underestimated the weight of the word "genius."
"Limited" only applied when comparing Bulma to top-tier scientists like Dr. Brief or Dr. Gero. Against regular researchers, she was already leagues ahead.
(Looks like I should find time to pitch the "Gravity Training Room" idea to Bulma and get that training method developed early…)
Hikari chatted with Bulma a bit longer, verbally locking in a departure date for the *Demon Slayer* world, then said her goodbyes.
She flew straight to the Sacred Land of Korin and climbed the tower to visit Korin.
It was clear Korin was a bit delighted by Hikari's arrival.
After all, Korin Tower was isolated from the world. The Kami up above rarely came down, leaving this lonely old cat with no one to talk to, passing the time by observing the world below. It got pretty lonesome. Hikari had anticipated this, so she came bearing a ton of gifts—
A stack of manga, novels, DVDs, and two DVD players.
"What are these? Human-world inventions?"
"Yup, stuff to help you pass the time."
Too bad the entertainment industries in the *Dragon Ball* and *Naruto* worlds weren't that advanced. If she could bring over 21st-century Earth's entertainment products, Korin wouldn't have to worry about boredom for decades.
After a quick lesson on how to use the DVD player, complete with a hands-on demo, Hikari listed the issues she'd encountered while training her "ki" recently, asking Korin for guidance.
That night, Hikari cooked dinner using the kitchenware she'd left behind last time and stayed on the tower.
She hung around for three or four days before preparing to head back.
This time, Hikari didn't ask for any Senzu Beans.
She'd already taken a big bag last time. Even though Senzu Beans were plentiful now—Korin had several jars—and Korin himself didn't care much about them, she couldn't keep asking too often and risk annoying him.
As long as she dropped by now and then to build rapport, she could eventually walk away with a few jars and achieve Senzu Bean freedom.
—Better she take them than let Yajirobe eat them all later.
As for the Kami up in the Lookout, she'd probably need Korin's introduction to meet him…
But.
Though Hikari didn't bring it up, as she was about to leave, Korin suddenly called out to her.
"What's up, Master?"
"…This old cat never agreed to be your master," Korin grumbled, brushing off the title. Then he continued, "Didn't you say last time you wanted me to give you a Nimbus Cloud? Besides the golden ones, there's also a black kind. These don't require a pure heart—even someone with an evil heart can ride them. If you don't mind it looking a bit ugly, you can take one."
As if to prove his point, Korin waved his staff, and a purplish-black cloud zipped in from the sky, landing inside Korin Tower.
"Eh?"
Hikari studied the black Nimbus, a faint suspicion forming. She asked, a bit awkwardly, "Master, you're not planning to yeet me off mid-flight, are you?"
**(End of Chapter)**