Fen: Hello boys! I'm baaaaaaaaaaaaaaaaaaaaaaack!

Striberx: And once more with another collab story idea.

Fen: Yup! That's right! After my two month vacation from the Philippines, the new and hopefully improved me is finally back to writing! And what better way to do that than writing a Dr. Stone fanfic!

Striberx: Something I was kinda surprised when he asked for my help.

Fen: The show is awesome! It actually teaches you science stuff! Ironically, it's one of my weaker subjects in highschool.

Striberx: Same, but I was still interested in the concept of it, and grew to like the show.

Fen: Same here.

Striberx: So, not much will change other than the introduction of a few extra stuff for our characters being added.

Fen: Right and before we actually start, I need to address a few things. As you can see, I enjoyed my two month vacation from the Philippines, and am now back home. During those two months, I took the time to reflect on things about my writing. And after contemplating and such, I figure it's time for a change. So first off, there will be no more opening theme songs. As much as I love them because of the aesthetic to see the story like an anime, I have to let it go. Yeah, go ahead cheer on, people who think anime openings are unnecessary, you got your wish.

Striberx: Reflection on writing is always a good thing and can lead to many changes and improvements, so don't forget that.

Fen: Let's see… what else to address… oh, second, as of now, anonymous reviews will officially be taken off, because I know those who are… displeased with my works tend to spam everything and I do not need that filling up my entire review sections. And to those who officially review, if you ever spam your hateful messages at me, I will report you. I've tolerated your hatred time and time again, but no more. You've forced my hand this time. I'm not doing this because you think I have some form of high strung ego. No, the reason I'm doing this is because people like you have no concept of human decency or constructivity. If you are going to hate, keep it to yourself out of respect for others who are trying to enjoy the story for what it is. Huh… sorry about that, I needed to get that off my chest.

Striberx: Hey, shit happens. At least you're taking the stance and getting things done and resolved. We also do plan to continue Fairy Tail, we're just having more debates and considerations with the future of the story. So until that gets resolved and we have a good conclusion? This is the replacement story that'll keep you all here.

Fen: Yeah. Alright, one last thing before we start. My Pen Name is going to be changed. While the old name stuck with me for years and is recognizable, I think a new one having more meaning to it is in order. And, the name… well, you're gonna get a preview of what to expect later on in my new Kamen Rider GX! *Pulls out a Rider Belt and attaches it to the waist. A belt comes out and is wrapped around it.*

DUEL DRIVER!

*Takes out a metal like Deck Box and inserts YGO cards into them*

DECK SET!

*A techno tune plays while doing an OOO stance before thrusting the Deck forward.* Henshin! *Inserts Deck Chamber into the Duel Driver*

DRAW YOUR CARDS!

*The Heisei Rider symbols appear one by one, positioning themselves in a vertical oval in front. The symbols spin around until the oval become solid and a blue holographic card takes its place. The holographic card flips over to show the armor before it pulls back. The armor pieces fly out of the holographic card, floating in place as the bodysuit forms, and the helmet and armor attaches itself.*

IT'S TIME TO DUEL! DUELIST!

KRD: Ja-jaaaan! Introducing Kamen Rider Duelist!

Striberx: Huh… odd change, but that's your call man. Sometimes even rebranding can help.

KRD: Yeah, well anyways, let's officially start… wait, do we even have a title for this?

Striberx: We do now!

Dr. Stone: Future Formula

Disclaimer: We do not own Dr. Stone. All manga creative rights belong to Riichiro Inagaki and Boichi! All anime creative rights belong to Shinya Iino, Yuichiro Kido, Tatsuya Kato, Hiroaki Tsutsumi, Yuki Kanesaka, and TMS/8PAN. Any and all insert songs that may be in this story don't belong to us at all either. In other words, we don't own anything, except our OC's.

Science.

The systematic study of the structure and behavior of the natural and physical world by watching and experimenting.

Since prehistoric times, knowledge and techniques were passed down orally from generation to generation. The development of writing enabled knowledge to be stored and communicated across those generations with much fidelity. And many ancient civilizations often infer their influence on human society.

For the past two million years from the Stone Age to the Modern Era, humanity continued to learn. The scientific method developed, where its methodology made significant progress. Technological developments and agricultural innovations were made. And the Scientific Revolution marked the emergence of modern science, transforming views of society about nature.

Thanks to science, humanity has progressed and evolved throughout history through its usage and has led to many discoveries.

However… all of humanity's progress thus far, will soon come to an abrupt end.

Monday June 3, 2019

"Listen up, Senku!" A voice yelled out as someone slid a door wide open to the science classroom. This is Taiju Oki, a young man that some of his classmates knew to be simple-minded, but is an outgoing, friendly, straightforward, and honest person. He has short spiky brown hair and has a sturdy strong body, with thick eyebrows and matching colored eyes, wearing your typical high school uniform. "I've made up my mind! I'm going to confess the feelings I've had for Yuzuriha for the past five years!"

"Heh~?" A bored voice moaned out uninterestedly as he turned to his friend. This is Senku Ishigami, a young male that's a genius with a vast amount of scientific knowledge, inventing various kinds of tools and gadgets in a short amount of time with ease since he was a child. He has an average build with his characteristic hair having two bangs going across his eyes and the rest sprays up, like a plant. His hair is a light, dirty blonde with dark green tips and has red eyes. He wore his school uniform while having a lab coat over him. "Well, that does sound interesting. I'll be cheering for you so hard, my vocal cords would snap… from here in this science lab." He said, placing a jar of some kind of liquid into a strange contraption that he built.

"You will!?" Taiju asked excitedly, the genius covering his ear with a pinky from how loud he was. "Thanks, Senku!"

"Shut up. I'm not cheering for you one millimeter, you big oaf."

"Wha-!?" Taiju gawked at his childhood friend in shock. "But you said that you would cheer for me! Make up your mind!"

"Like you're one to talk when you haven't said anything to Yuzu-chan for the past five years." Another voice said, as he came into the science classroom. This was Kurogasa Kururugi, a young male who appears on the outside to be quiet and polite, but according to comments from his classmates, he is actually dependable and friendly. He had unkempt brown hair with a fringe that's fanned out and has blue eyes, wearing the same highschool uniform. "Sorry about that, Senku. He just doesn't know when to stop."

"You don't know what it's like, Kuro!" Taiju exclaimed.

"Of course I do," Kurogasa replied. "I confessed to Yuzu-chan and she rejected me. Plain and simple."

"You did?!" He gasped, grasping his shoulders before shaking him violently as he yelled at him in dismay, "Why did you keep this from me!?"

"Uwhaaaaaaaaaaaa, Taiju, stop!" Kurogasa cried out, his head thrashing around and his vision moving all over the place. "Senku, do something!"

"Why? This is enjoyable to watch." He snickered.

Taiju kept shaking the poor boy until he was suddenly bonked on the head. "OW!" He cried out in pain.

"Taiju-kun, I told you that Kuro-kun hates being shaken." A feminine voice called out.

"Remember, both of them are thick headed." Another male voice chuckled.

Coming into the science classroom were two more people, who also happen to be childhood friends. One was a young girl with long brown hair and eyes of the same color. She had a slim build, wearing a standard high school uniform for girls and wears a white hairband that's vaguely shaped like wrap-around headphones. This was Yuzuriha Ogawa. She's a kind individual who tries to help her friends and strangers alike in whatever way she can, though she can be quiet and while not overly shy, is usually reserved sometimes.

The one next to her was a young male with short, yet messy dirty blonde hair and has blue eyes while wearing glasses. He had a firm build, but not to Taiju's extent, and was enough to pull some weight. This was Cody Aldrich, an exchange student from the United States and a sympathetic guy who does his best to help others, both human and animal alike.

"Cody, Yuzu-chan," Kurogasa groaned, being dizzy from Taiju shaking hm.

"Y-Yuzuriha!" Taiju flinched, letting go of Kurogasa as he dropped to the floor.

"Ow! Don't drop me like dead weight!" He snapped.

"Ten billion points to Taiju." Senku snickered.

"Hey!"

"Are you alright, Kuro-kun?" Yuzuriha asked as he knelt down to him. "I'm sorry about Taiju-kun. You know how he gets when he finds out about something." She apologized.

"Oh no, it's fine, Yuzu-chan. I'm used to it." Kurogasa laughed sheepishly, rubbing the back of his head.

"By the way, we saw Mrs. Yukina while coming here. She has something for you." Cody informed Kurogasa.

"Huh? Oh, alright. I'll go see her now." Kurogasa said, picking himself up, with Yuzuriha standing up as well. He then fished out of his pocket a gold-plated koban coin, before throwing it to Senku to which the latter caught. "Here you go. Have fun flaking off all that gold for your next experiment."

"Heh, I'll have it skinned before you even get back." Senku smirked.

"Wait, where did you get the money to buy gold!?" Taiju gawked.

"I got it from the gift shop." Kurogasa deadpanned, with a twitching eyebrow. "It may be 24-karat, but it's gold plated, meaning the inside isn't gold, ergo, it doesn't hold that much value."

"Uh… what now?" Taiju blinked in confusion.

"It's cheap." Cody translated, trying to stave off a headache. Why was this so painful to watch? They knew he was simple-minded, but even he should've known that.

"Oh, gotcha." Taiju nodded in understanding, making his friends sigh.

With a wave goodbye, Kurogasa walked down the stairs of the school, making his way down the hallways, before arriving at the school entrance. Standing there waiting for him was a young woman in her late 30's with long flowing pink hair and gray eyes, wearing a beautiful kimono. This was Yukina Kururugi, the matriarch of the family, best cook in the world in Kurogasa's opinion, and overall doting mom who can't keep her hands off her son.

"Ah, Kurogasa!" Yukina smiled, hugging her son affectionately.

"Kaa-san, what are you doing here?" Kurogasa asked with a slight groan before Yukina broke the hug. While he loves his mother to death, the affection was a little too much.

"You forgot your lunch again." She smiled, holding up the bento.

"Eh!?" He gawked. This was the third time this week! With a sigh, he slumped his shoulders and hung his head. "Oh man, no wonder I've been hungry all day…"

"That's why I decided to add a bit more, and bring it!" She beamed lovingly, "Plus I missed you already, so I had to take this chance."

"You really didn't have to." Kurogasa frowned.

The mood suddenly changed from happy to sullen as his mother looked at him with a saddened expression. "Of course I do. What if I waited at home and you never came back…?" She murmured.

Kurogasa frowned sadly, "Kaa-san… don't say stuff like that… I'm not gonna leave you alone…"

"But it could happen! And my heart wouldn't handle it… not after your father passed away."

"It won't. I won't let that happen, because I'm keeping our family alive." Kurogasa said, before wrapping his arms around her. "So don't say those things. Because I'll always be there for you."

Yukina couldn't help but smile. He was always thoughtful, taking into consideration her feelings, and doing the best he can for her. "Thank you…" She sniffled, breaking the hug while wiping her tears away. "I-I'm sorry… I didn't mean to get so emotional."

"No, it's fine." Kurogasa shook his head, with a sad smile. "I know Tou-chan isn't around anymore so it's up to me to pick up where he left-" He stopped mid-sentence when an eerie green light shone on the horizon, and both he and his mother looked towards it. The way that the green light was radiating had them very anxious. Something definitely wasn't right.

"W-What… is that?" Yukina got out, her voice slightly trembling.

"I don't know." Kurogasa replied, as he stepped forward to get a closer look. But the moment he did, a mysterious green wave of energy suddenly washed over them, causing them to stand their ground. "Kaa-san, get behind me!" He exclaimed. Yukina managed to do so and her son placed his arms in front of him to guard himself from the mysterious energy. But as this happened, he noticed something very wrong. His body was turning gray and was hardening!

'No! Why is this happening!? What's going on!?' Kurogasa cried out in his thoughts. And before long, his entire being was encased in solid rock.

"Kuro…" Yukina uttered out, as she too met the same fate.

Not only did it affect them, but it also affected their friends and everyone else, as the mysterious energy washed over the entire planet.

Thus humanity was turned to stone.

Chapter 1: Stone World

On Monday June 3, 2019, all of humanity was petrified and the world returned to its primitive state. Where did it come from? Who started it? None of that matters as the result is that of an Earth without humanity, where the remains of civilization rotted away, allowing nature to take its course. After the petrification, vehicles in motion lost control and crashed. Flora and fauna were allowed to grow unimpeded, while buildings and other human structures eroded and collapsed. And natural disasters, such as flooding and volcanic eruptions, occurred without human interference.

For centuries, Kurogasa was trapped in his stone prison. The only thing keeping him alive and conscious were the thoughts of his mother, hoping that she was still alive. He needed to stay conscious if he was to break free from this darkness and find her. Unfortunately, his senses were blocked in his petrified state. He can't see, hear, smell, feel, and/or taste. It was akin to sleep paralysis, being unable to move or speak that occurs when waking up or falling asleep. But none of that matters. He has to focus on getting out of this darkness and finding the light!

*CRACK!*

What was that sound? He could barely hear, but it sounded like a…

*CRACK!*

There it was again, that noise.

*CRACK!*

Light… he saw light in front of him as the stone that covered his eye broke off! If he needed to get up and start working, now was the time!

"Grrr… grrr…!" Kurogasa gritted as he felt movement in his body. He managed to wiggle his arm and before long, he broke his arm free of his stone shell and the other soon followed, "Graaaaaagh! Graaaaaaaaaaaaaaaaaaaaaaaagh!" He yelled as he used all of his strength to finally break free from his stone prison. "Gahhhhhhhhhhh…!" He breathed heavily, taking in so much air that he coughed up a storm, falling to one knee before steadying himself and calming himself down. "I did it… I broke free…" He panted heavily, shakily standing up. He looked around and noticed that he was in the wilderness, covered by trees and plants that grew significantly. Another thing he noticed… was him being naked!

"Heh, welcome back to the living, Kurogasa." A familiar, snarky voice called out to him.

Kurogasa didn't voice out his surprise from the fact that he had no clothes, but instead voiced out a noise of confusion as he looked up to see someone standing on a branch of a tree. They were clothed in what looked to be animal skin clothing in a rudimentary manner, that was almost cavemen-like. And the famous equation E = mc² was written on their left lapel. He gasped in surprise when he saw who it was. "Senku? Is that you?"

"Heh, ten billion points to you." Senku smirked, hopping down before handing him the same type of clothing, he had on. "Come on, we have lots to discuss."

"Uh… yeah." Kurogasa replied, with a dumbfounded look, taking said clothes. Putting them on, his new clothes now consists of a tan karate gi with the sleeves torn off, while having a rope belt to keep his pants up. "Been awhile since I've been in these." He commented, giving himself a once over.

Senku then led the teen through some dense forest and more. While following Senku, he noticed the many statues of people littering the ground. They were still alive, just trapped inside their stone prison, though some of those statues were broken or weathered away, meaning there was no chance of them being freed anymore. It was the same as being dead. 'No way… it happened to everyone…' He thought. Soon, he was greeted by the sight of a small treehouse that looked decent, but definitely took many attempts to have it the way it is.

"UWAHHHHH, KUROGASA!"

In moments, he was bear hugged by Taiju, squeezing him with all of his might.

"GAHHHH! TAIJU, WHAT THE HECK!? GET OFF ME!" Kurogasa shouted, trying to push him away.

"You're okay! You're really okay! I'm so happy, I could just kiss you!" Taiju cried out happily, as he actually tried to kiss him.

"Dude, I'm not gay! Get off!" Kurogasa snapped, kicking Taiju off of him and the latter tumbled to the ground. "Geez Taiju, first thing after I get out, you squeeze me to death!" He huffed, dusting himself off.

"Sorry…" Taiju apologized.

"Relax, he's just happy that you're alright." Senku waved off.

"So, he's finally up? About time." Cody snickered, coming out of another side of the forest with some fauna and other plants in some baskets. His attire consists of the same material as the others, but was designed like a shinobi, as it was a darker blue with a few pouches on his belt.

"Cody?" Kurogasa gasped. "You're alive!"

"Yeah he is. Look, as sentimental as this is, I didn't revive you just for good old times." Senku reminded.

"Huh? O-Oh right." Kurogasa said, but then panic suddenly seeped into his being. "Wait, where's Kaa-san!? Is she-"

"Relax. She and Yuzuriha, are still intact in stone." Senku assured, only to hold up an empty cup, "Though I had to use the last one in stock to revive you."

"You-"

"Look, it's best that you sit down so I can explain it." Senku suggested, pointing to the campfire that was surrounded by sticks of mushrooms roasting nearby. "Besides, you look like you could use something to eat."

"Mmm…" Kurogasa frowned, as he did feel hungry. Who could blame him since he's been trapped for who knows how long? Senku and Kurogasa walked over to the bonfire and sat down before the latter took a cooked mushroom kebab and chowed down. "Alright, so what's going on?" He inquired.

"Well, to start, we're roughly 3,700 years into the future." Senku answered. "3,719 if you want to get specific."

Kurogasa stopped eating when he heard his answer, no doubt in shock and surprise. "3,700… years?"

"Yeah. As of today, it's Thursday, October 9th, 5738."

"No way…" Kurogasa whispered in disbelief. He was trapped in his stone prison for that long? The fact that he managed to survive that long before breaking out was a miracle. But how did Senku know what year it was? It's impossible to calculate how much time has passed while in a petrified state. Unless… "Have you been counting ever since we turned to stone?"

"Yup. That's what kept me from losing consciousness. I'd peak every 800,000 seconds or so. If I were to wake up at any point during winter it would have been game over. So starting in spring was crucial."

"How long has it been since you got out?"

"Six months." Senku answered. "Since then, I've been surviving on my own, making stone weapons, combusting fire, and building this treehouse, along with a laboratory I set up. That is until I found Taiju, Cody, and recently you along with Yuzuriha and Yukina-san."

"Well, you certainly didn't waste any time." Kurogasa mused, looking at the tree house that he built before looking back at the genius, now noticing the visible scars on both of his eyes. "What's with the scars?"

"A side effect from the petrification."

"Then… I guess I have one too." Kurogasa said, as he touched his face with his free hand all over, before feeling the scar starting on the left side of his eye on top and trailed downward until it ended up at the bottom. "Great, I'm Weiss Schnee from RWBY…"

"Isn't she one of your anime crushes?" Senku snickered.

"Shut up…" Kurogasa hissed in embarrassment.

"Heh… anyways, I probably don't need to tell you this, but as you can see all around us, every human on Earth turned to stone."

"Every human…" Kurogasa frowned.

"And sparrow."

"I was wondering about that. All the sparrows were turned to stone the day before."

"It also stands to reason that those sparrows were the test run. And we were the main target."

"Don't tell me you came up with theories as to who did it." Kurogasa raised an eyebrow with incredulity in his eyes. His face soon deadpanned when he saw Senku's grin, and it was all he needed to know. "You did, didn't you…"

"A lot of theories…" He chuckled, "But I narrowed them down to three main possibilities that seem plausible. The first theory is that some kind of alien race attacked Earth and decided to petrify us for whatever reason. Another is that some country made a superweapon that went wrong, and it backfired. And the final one is that it was some sort of new strand of virus. But… without any real evidence, it's only that, theories."

"I still say it was dino people from underground." Cody huffed.

"That's rather illogical coming from you." Kurogasa sweat dropped at Cody's conclusion. "Plus, I don't think any of those other theories work either. But I digress. So… have you been working on a cure?"

"I did revive you after all." Senku smirked.

"Right." Kurogasa nodded. "Well, I think I got the jist of it. Knowing you, you're gonna do all you can to find out why everyone turned to stone. That also means that you'll be curing everyone. Though I have to admit, reviving seven billion people is a tall order."

"True. But it's a challenge I'm willing to take. Of course, I can't do it alone. Hence why you three were revived."

"And I don't need to guess why. You revived me cause I'm a fanatic of rocks, metals, and crystals."

"Heh, that's right. One-hundred million points for you." Senku smiled widely.

"Figures." Kurogasa chuckled before biting down the last of his mushrooms. "Alright then, consider me joining the party, Senku. We'll rebuild civilization from scratch and figure out the petrification mystery while we're at it."

"Good answer." Senku grinned. "But first, we need to start mass producing the miracle fluid."

Kurogasa tilted his head in confusion. "Miracle fluid?"

Senku led Kurogasa far away from the campsite until they reached a cave. Going inside, the teen scientist pointed at what's inside and Kurogasa peered in to see a clay cup on the ground, collecting what appeared to be yellow water. He also noticed at the top cave, a group of bats that were sleeping.

"This… is the miracle fluid?" Kurogasa asked as he placed his fingers under the stalactite and the yellow water dripped on them.

"Best to taste it before anything else." Senku chuckled.

Kurogasa frowned at him at the joke, rolling his eyes before looking back at the yellow water he had on his fingers. He brought it to his nose and sniffed it. "Nitric Acid." He said with wide eyes.

"Correct." Senku nodded. "I'll be honest though, I haven't found the cure yet. All of us boys have been cured via nitric acid alone made from bat guano. It took me a while, just to get enough to use on you three. Only small drops work. But I did find a better solution to progressing the cure. If you combine it with Ethanol then it makes Nital, an industrial etching agent."

"I read something about that one time." Kurogasa mused. "Sometimes blacksmiths use an etching agent if they want to engrave something into a weapon. And it corrodes stone too."

"And if we add alcohol, it helps make the agent act faster, thus removing the petrification." Senku added.

"But… given how slow the nitric acid is dripping…"

"That's why we have the pot to collect it."

"Right…" Kurogasa trailed off. "I just hope it's enough to revive Kaa-san and Yuzu-chan…"

"One cup is enough to revive a person. But like I said, I used the last one, for you." Senku reminded him, "It'll take time to get more, but it can be done."

"Yeah…" He muttered as he looked back outside of the cave and at the sky. The rocky cliffs were littered with statues, some broken or eroded, while covered by plants and vines. "3,700 years of human history lost… history, humanity would have made if not for that day… if we weren't petrified, humanity would have progressed even further and it'd be a lot easier for everyone. But… either way, we won't see that kind of future in our generation…"

"Kuro…"

"I made a promise to Kaa-san, Senku." Kurogasa muttered, clenching his fist tightly. "I made a promise to keep my family alive for as long as I live and I'll be damned if I don't keep it. After all… I'm-" He felt a hand on his shoulder, making Kurogasa look at the other boy.

"I get it. No need to say anymore. As long as you're alive, there's hope. Luckily, your mother's stone body is next to Yuzuriha, so we know where to look."

"Yeah," Kurogasa nodded, before punching his fist. "But before that, let's get started on what we need to survive. Tell me what to do, Senku."

"Just gather some minerals and materials from deeper in the cave."

"Okay." He nodded. Senku then lent him a stone axe he carried and Kurogasa went into the cave. But he stopped himself, as he wanted to say something. Looking over his shoulder, he said to the other teen, with a determined look, "Senku… I promise, I'll do everything in my power to help you de-petrify humanity. I owe you that much after you revived me."

Senku smirked, "That's the deal, after all. Everyone must put in their effort ten billion percent if we want this to happen, otherwise, we'd be better off extinct."

"Right. Let's do this!"

So the two of them gathered minerals and raw material for the next hour or two. It was definitely hard work as they didn't have the convenience of using technology they would've used from 3,700 years ago. The only light they have was sunlight from the outside world and they had to be careful using their stone weapons when hitting it against other rocks and raw materials, or else they would break. Once they felt they gathered enough, they began walking back towards base. As they traversed through the wilderness, Kurogasa noticed one of the statues in the distance. Sitting on a rock was a statue of a rather muscular teenager with long flowing hair and stern eyes. "Hold on, I think I've seen him before on TV. Isn't that the strongest primate high school fighter, Tsukasa Shishio?"

"Hm?" Senku looked over to where Kurogasa was seeing, "Oh yeah, I've heard about him. He could be useful someday."

"He's been fighting in MMA for quite a while, hasn't he." Kurogasa mused.

"Yeah, but I heard that he has no sympathy towards his opponents. I don't know if that would work well, if he's to be in our group." Senku frowned. "Only if we're about to die, would I revive him."

"That might be a good idea." Kurogasa nodded in agreement, before they moved along. "You think… we're really the only ones de-petrified? Maybe there were others that survived."

"Hard to say, really." Senku shrugged, "But if we weren't, there would've been something long ago."

"Right. But… I wonder…" Kurogasa trailed off with a pondering look on his face.

"Hm?" Senku looked at him with a raised eyebrow.

"Your old man, Byakuya. He was an astronaut, right?" Kurogasa questioned the teen scientist.

"Yeah, why?" Senku asked back.

"He was in space at the time. If he were in space with other people in the International Space Station… wouldn't that mean they weren't affected when everyone turned to stone?"

Senku gasped in mild surprise. He hadn't really thought of that. When the World Petrification happened, it only affected everyone that was on the planet surface. But the mere idea that his old man and other people from the space station surviving the petrification, would imply that somehow, there are descendants of Byakuya and those that survived with him. The more Senku thought of this, the more it started to make sense.

"That… is possible…" Senku finally said.

"And knowing your old man, I don't think he's the type to give up so easily." Kurogasa added. "Maybe he left something behind for you, once you got out of your stone prison."

"Perhaps…" Senku pondered. "If there is a slim chance that he did leave something for me, it'll make me happy to see."

"Yeah, I bet." Kurogasa agreed. "And I'm sure whatever he left behind, you'll use it to its fullest extent."

"Definitely." Senku chuckled. "The mere thought of my old man helping me out like that, it's kinda exhilarating."

"Hey guys, we're back." Kurogasa called out as he and Senku had just arrived at base camp with their rocks and raw material.

"Welcome back." Cody greeted them. "We found some unique plant life this time. Some that I think almost went extinct during our era." He said, holding up the specimens.

"And I got a lot of mushrooms and other edibles!" Taiju added, bringing in a whole basket as well.

"Huh…" Senku mused, before he took the basket and sat down, sorting them out what's poisonous and what's not. "Amanita virosa: poisonous, Buna shimeji: edible, Amanita muscaria: poisonous."

"Taiju, this isn't Mario…" Cody sweat dropped with a sigh. "What else did you get?" He said, as he went through the basket as well. "Mugwort: edible, Monkshood- ARE YOU TRYING TO KILL SOMEONE!?" he cried out comically.

"What? It looked pretty." Taiju blinked in confusion.

"That's not the point, you big oaf. You can't just pick 'em off so carelessly and hope for the best." Senku sighed. He knew the big oaf was simple-minded, but he should at least have a bit more common sense when it comes to these things.

"The only good thing we can use them for is making antidotes. Then we can add more to our antivenom collection once we have the right materials to extract them." Cody replied as he helped Senku sort out more of the basket.

"So in other words, keep scavenging." Kurogasa patted Taiju's shoulder. "Oh, that reminds me. Taiju… Can you take me to Kaa-san and Yuzu-chan? I need to see them."

"Sure thing, Kuro," Taiju nodded.

"We'll be back." Kurogasa waved to Cody and Senku, who waved back to let them go.

Taiju led Kurogasa through the woods, following the river upstream and after a while, the two of them arrived at a huge camphor tree, that grew almost the size of a sequoia. Kurogasa took note that it was where their school once stood and that the big camphor tree was the same that was planted near the school entrance. He could imagine in his mind, the high school that he and his friends once attended, what used to be is now gone forever more. Looking back to the tree, he saw two statues resting on its roots against the trunk and they were both female, one older and one younger.

Kurogasa then climbed up the roots of the camphor until he was at the top of them and approached his mother's statue. Finally, after so long, he had found her and thankfully she wasn't broken. "Kaa-san…" He muttered as he looked at his mother, tears falling from his eyes in relief before wiping them away. "Thank goodness… you're still intact. Don't worry… Senku, the others, and I will get you out… just wait a bit longer."

He then looked at the statue of his other childhood friend. "Yuzu-chan… thank goodness, you're intact too. Taiju would be devastated if anything happened to you." To him, he was like the little sister he never had. Sure, back then, he used to feel differently about her, but things have changed and it was actually for the better. "Hey Taiju… remember when I told you that I confessed to Yuzu-chan and she rejected me?"

"Hm? Yeah. What about it?" Taiju blinked only to gasp, "Wait! Don't tell me that you're still in love with her!"

"Hehehe… don't worry. I wanted to tell you, before we all turned to stone, that my feelings for her have changed. It's more of a sibling love now." He looked back at him with a sad smile. "Though it doesn't mean I'm not hurt. Even now, it still kinda stings."

Flashback

"Yuzu-chan, I need to tell you something." Kurogasa said as he and her were on top of the school roof one day, the two of them being alone. He needed to get it off his chest. He held in his feelings for so long, but now he can't contain anymore. He needed to tell Yuzuriha about how he feels now.

"I already know, Kuro-kun." Yuzuriha said, smiling at him.

"Huh?" Kurogasa looked surprised.

"I know that you've had a crush on me."

"Y-You did?" Kurogasa stuttered. How did she know!? He was going to tell her how he felt, but somehow she already knew?! "S-Since when?!"

"Since we were little, silly." Yuzuriha giggled. "You, Cody-kun, Taiju-kun, and Senku-kun have been friends with me ever since kindergarten. It doesn't take rocket science to figure it out."

"Well no, but… I just wished I had the chance to say it." Kurogasa chuckled sheepishly. "You're kind, helpful, and always look after everyone. I mean… what's not to like about you for that?"

"Hehe, I appreciate it, Kuro-kun. But if I'm being honest? I can't see myself falling in love with you." She said, not wanting to be rude, but needed to tell him the truth.

"!?" Kurogasa looked shocked. "You… don't?"

"No…" She shook her head, "You're much more important to me than that. I see you as a brother, someone I care for so much I can't help myself but be happy."

"A… brother, huh?" Kurogasa looked down with a sad smile.

"I'm sorry, Kuro-kun."

"N-No, it's okay." Kurogasa tried to put on a brave face but the tears fell anyway. "I-I understand. It hurts… but… I can live with that…"

"Kuro-kun…" Yuzuriha said softly. She then approached and hugged him while he spilled his heart out. "It's okay… let it all out."

End Flashback

Kurogasa looked down, as he smiled fondly at the memory. "Eventually, I came to accept that Yuzu-chan doesn't see me like that. She's now my sworn little sister that I have to protect."

"WAAAAAAAHH, WHAT A SAD TALE!" Taiju bellowed in tears as they streamed like a waterfall. "Yuzuriha is so kind!"

"And you just ruined the moment," Kurogasa sighed. Talk about a mood killer. "Well anyway, I just wanna say that I'm over it. So you have a clear path to her."

"Kurogasa…" Taiju muttered, as the former got down the roots and approached him, placing a firm grip on his shoulder.

"But… if you ever hurt her or make her cry in any way for whatever reason…" Kurogasa muttered darkly, before making a hand gesture of crushing something. "I'll castrate you…"

"You know I'd rather jump into a den of lions than do that!" Taiju exclaimed, only to headbutt Kurogasa who stumbled back and fell on his butt, "And I should say the same to you! If you make her sad, I'll make sure you regret it!"

"Hehehe… hehehehehehehe… HAHAHAHAHAHAHAHAHA!" Kurogasa laughed, holding his head. This confused Taiju greatly. What was he laughing about? "That's the first time you actually hit someone willingly! You never hit anyone, even when we were kids!"

"Eh? I did?" He blinked, then thought about it, before he came to the realization, his skin paling so bad. "WAH! I'm so sorry!"

"Hahahahaha, no it's fine, really. At least you got your point across." He said with a chuckle, before standing back up on his feet. "And we'll both do our best to make Yuzu-chan happy."

"Yeah!" Taiju nodded.

"Now then… if we're gonna make the miracle fluid, we're gonna need nitric acid, but we need some alcohol too. If only we had liquor or something…" Kurogasa pondered, placing a hand on his chin.

"Liquor? But… couldn't we just make wine with grapes?" Taiju asked.

Kurogasa looked at Taiju for what seemed like forever. In mere moments, the revelation hit him like a ton of bricks thrown at his face. "HOLY CRAP, TAIJU, YOU'RE A GENIUS!"

"Huh? I am?"

"Yes!"

Kurogasa and Taiju went on to gather all the wild grapes they could find and get around the area and brought it back to base. Once they told Senku of the discovery Taiju made, they set to work crushing all the grapes they gathered into juice. Well, it was mostly Taiju since he did most of the crushing with his bare feet. Once it was done, they placed all the juice into a container made out of clay and kept mixing all of it for the next three weeks, until they finally made wine.

"Who would've thought Taiju would be a genius in making wine?" Cody snickered as he swirled his cup of wine in his clay cup. "I'm legit surprised."

"Even idiots can be smart sometimes." Senku smirked.

"Wait, wouldn't this be considered underaged drinking?" Taiju questioned with concern.

"Well chronologically speaking, we're already over 3,700 years old, so we're totally fine." Kurogasa said, before taking a sip. But the moment he did, he immediately spat it out. "Pffffffft! Gah, this tastes terrible!"

"Hehe, we did make it out of the blue. Wine is meant to be preserved and fermented before that. Which takes several decades." Cody informed him.

"One step at a time." Senku replied, bending his neck from side-to-side as it cracked. "Things are about to get a little more tedious, from here on out. Distilling Wine for Dummies, starting with brandy."

"Distilling? I have no clue what that means." Taiju said.

"You heat it, cool it, and drip it. That's what concentrates the alcohol." Kurogasa explained to him in simple words that Taiju could understand. "The Mesopotamian civilization started doing that in 3000 B.C. using clay pots."

"Which means, we need to make more pots…" Cody said, with a groan of dismay. "I hate arts and crafts…"

"Sadly, we don't have a choice." Kurogasa patted his friend's shoulder for reassurance. "It's times like these that we have to put up and shut up."

"Yeah, go figure. Oh well… nothing like the present."

For the next year or so, they have worked tirelessly to sustain themselves and gather more materials needed for survival. The days were uneventful for the most part as each contributed to their work. On Kurogasa's part, he went collecting more of the minerals and rocks that were in the surrounding area, as well as collecting sand and ore deposits. When the time comes he will use those materials, to thrust himself into the Iron Age.

For Cody, he did what he could to siphon the alcohol from the wine they made, since he knew many things due to his training. He would take a few short rests here and there, since he was used to not eating for a few days. This was too important and he needed to get this done for everyone.

Taiju did most of the hunting and gathering, gaining mushrooms and even a few small animals like rabbits and in rare cases a deer or a boar. During the winter, he had grown a beard and had Senku find a way to get rid of it. He needed to look good in front of Yuzuriha once she was free from her stone prison. When Senku found a couple of seashells, he rapidly plucked the hairs off his face until there was no facial hair. It was so red and swollen that Senku cracked up, laughing his butt off.

When spring finally came around, they tested more on the sparrows that Senku had found way earlier before reviving the other three boys. After what seemed like forever, they had a breakthrough as Taiju's sample broke the stone of a feather into pieces to reveal the feather trapped inside.

The four boys then walked outside of the lab and set a sparrow on the ground. Taking Taiju's sample, he poured it all over the sparrow. "Let me teach you guys," Senku began. "It's not that there are things that science can't explain. You look for the rules behind those things."

*CRACK! CRACK!*

"Science is just the name of the steady, pain-in-the-ass effort that goes into doing it."

*CRACK! CRACK! CRAAAAACK!*

With each passing second, the cracks on the sparrow statue became larger until it became a web of cracks, traveling along the stone before it finally shattered, freeing the sparrow and letting it soar into the sky for the first time in 3,700 years.

"UWHOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOA! WHOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOA!" Taiju roared in happiness as the sparrow flew around the base in circles before flying away to the sky.

"No way… we did it…" Kurogasa smiled widely. "WE REALLY DID IT!"

"Our Stone Formula is finally complete!" Cody cheered.

"Hehe, with this we can release more power." Senku smirked as he sat down on the black pedestal, looking up at the sky with a tired but satisfied smile, the sweat of hard work and perseverance trickling down his face. "One year since we started experimenting. It didn't take as long as I thought it would." With a chuckle, he added, "It's a slow and steady effort. But I'm going to beat fantasy with science. This is exhilarating."

「"Stone Formula" acquired!」

Z=1 END