[Y/n] and Senku were busy collecting sulfur while Taiju and Yuzuriha was busy bathing.
"[Y/n]..." Senku began, narrowing his eyes at the ground.
[Y/n] looked at him and tilted her head. "If anything were to happen to me..." Senku continued, darkly while collecting more sulfur, "Please...run away as fast as you can with Taiju and Yuzuriha."
[Y/n]'s eyes widened a bit in shock, and she stared at Senku for a moment. She couldn't believe Senku would ask her to do something like that. [Y/n] glared slightly. "Absolutely not!"
"[Y/n], don't fight me on this. I just want you safe." Senku said.
"Senku! [Y/n]! It's your turn for a bath!" Yuzuriha called, and [Y/n] huffed while setting the bag down.
"Hmph! Gladly!" [Y/n] said and stood then walked ahead of Senku.
Once she got to the hot spring, [Y/n] stood on the other side of the little fence and took off her clothes then got in. She heard slashing on the other side, so [Y/n] knew Senku was there too. Her mind couldn't even be embarrassed at the presence of Senku.
[Y/n] angrily puffed out her cheeks. She was angry that Senku would ask her to do something so ridiculous.
"[Y/n], please." Senku's tone was gentle and pleading.
[Y/n]'s [e/c] eyes softened. She usually agrees with whatever he says, but this is something she couldn't bring herself to do.
"Senku...what I said a few days ago was the truth. I am useless and hopeless without you, Senku." [Y/n] said, softly, having a major effect on Senku, "I care about you, deeply, and admire you. I will not abandon you no matter what you say."
He didn't know if it was the hot air or [Y/n]'s words that had his head spinning. His knees almost gave out again.
[Y/n] placed her hand on her chest. She felt warm inside. The feeling that being with Senku gave her. Almost at peace.
"So, you're looking to die with me then?" Senku muttered with a reddened face.
[Y/n] smile a little, "Of course. We're partners until the bitter end."
She heard Senku let out a breathy chuckle, and Senku creaked his neck. "You make it sound like we're married." He muttered and shook the fantasy out of his head.
"And I'm ten billion percent certain you would hate being married. Especially to me." [Y/n] said and giggled. She used his catchphrase even though the fantasy of marrying Senku was rather pleasant to her.
"I see what you did." He said.
Yuzuriha and Taiju watch the two geniuses exchange little words with their faces turned a shade of pink.
"They're perfect for each other." Yuzuriha muttered.
"Really? Senku said he doesn't have feelings for [Y/n]." Taiju said.
Yuzuriha sighed. "He's obviously lying."
"What?!" Taiju was shocked at the fact, "I can't believe he would lie to me!" Yuzuriha giggled at his cluelessness.
"Senku..." [Y/n] called his name. The way she called his name always made Senku's heart skip a beat.
"Hm?" He hummed.
"Once we bring back civilization... I would like to start another experiment with you. Like before we were petrified." [Y/n] said.
Senku chuckled. "It could take years to bring civilization back." He said and cracked his neck.
[Y/n] smiled softly. "I'm patient. As long as it takes. I...just love being with you." [Y/n] said, and Senku blushed slightly.
"I lo-"
A sudden squeal was heard. Senku and [Y/n] turned to see a brown ball speed towards [Y/n] and splashed in the water.
"Inosuke?!"
"What is the pig doing here?!"
[Y/n] hugged the baby boar.
"He must have been asleep in my bag. I can't believe I've forgotten. I'm sorry. " [Y/n] said, while Senku glared at the water. 'I lost to that pig again!'
｡･:*:･ﾟ★｡･:*:･ﾟ☆
The next day, it was time to make the powder. Senku chuckled and pulled coal out of his bag.
"We have the three materials we need to make gunpowder." Senku said, and Taiju smiled.
"We have them already?" He asked.
"All we need to do now is mix it. It's time for our happy gunpowder cooking session." Senku said with a little evil smirk.
It was like a real cooking segment with [Y/n] as his assistant. Senku held up one finger and said, "Ingredient number one for gunpowder...Sulfur, which we can get plenty of at this hot spring."
[Y/n] poured the grided sulfur into the bag.
Senku held up two fingers. "Number two...Charcoal. We can get all we need by burning wood."
Senku said while tossing some in the bag.
Senku held up three fingers. "And number three, the last, but most difficult: potassium nitrate. It'll take a hell of a long time to make this stuff, so..."
Senku pulled out a bag that was filled with potassium nitrate.
"Kukuku! I've already made some to save us time!" Senku said, and [Y/n]'s eyes sparkled.
"Incredible!" She cheered while clapping her hands together.
"I feel like I've heard the word 'nitrate' somewhere...Nitric acid! Miracle Water! You got it from the cave?!" Taiju asked.
"You're right for once, simpleton. Ten billion points for you." Senku said while pouring the potassium nitrate into the mixture. "Potassium nitrate, sulfur, and charcoal all go into the mix and a pinch of sugar to give it a little more oomph. This glucose if what I made from grapes." Senku explained while adding the sugar while [Y/n] mixed the ingredients together.
Senku grabbed a nearby log. "Finally, pound it until it's packed solid!" Senku announced. Taiju picked up a large rock.
"Pound it, huh?! Leave the heavy lifting to me!" Taiju yelled, shocking [Y/n], Senku and Yuzuriha.
"Are you sure that's a good idea? You might be strong enough to make it spark and go boom! Like flint!" Yuzuriha panicked.
"Nah, you won't get sparks by hitting stone with stone." Senku said.
"Really?" Yuzuriha questioned, and Taiju tested it.
"Oh, you're right." Taiju said.
"Flint is more than just stone. It needs to have metal in it to make sparks." Senku said, and [Y/n] looked at him in shock then patted his arm.
"Iron pyrite!" [Y/n] shouted one of the compounds in their gunpowder mixture, making Senku realize his mistake.
"Wai-"
But it was too late. Taiju hammered the rock down on the bag, creating sparks. Inosuke squealed and ran while the four friends stared at the bags for a few seconds. Senku picked [Y/n] up bridal style while Taiju scooped Yuzuriha up, and the two men ran out of the way of the blast while being blown away in the process.
They all sat up and look at the remains of the blast, and Senku chuckled.
"No problem! Our gunpowder cooking was a huge success!" Senku cheered.
"I had no idea gunpowder was so powerful." Yuzuriha said, and [Y/n] stood then dusted herself off.
"There are many tales of science experiments involving gunpowder that have failed and blown off students' limbs." [Y/n] said while putting her hair into a ponytail then picked up Inosuke, and Yuzuriha sweat nervously.
"It can easily be lethal." Senku added.
"We're going to attack Tsukasa-kun with this?" Yuzuriha asked.
"No, we're going to make a deal." Senku said.
"Tsukasa-san isn't a mindless killer. He's very clever and strategic. Statistically, people like that tend not to turn down a negotiation if their life is in danger." [Y/n] explained.
"We have gunpowder, so we have leverage." Senku said.
'But if our negotiation fails... we'll have to...kill him' [Y/n] thought.
As they tried to extinguish the fire, [Y/n] noticed something in the distance, making her eyes widened in shock.
"S-Senku!" [Y/n] called and pointed int the direction of the smoke signal. Senku's eyes widened in shock as well.
"Tsukasa-kun?!" Yuzuriha questioned.
"No, that's in the opposite direction. Besides, Tsukasa has no reason to reveal his location." Senku said, and [Y/n] tapped the bridge of her nose, deep in thought.
"A forest fire?" Taiju asked.
"It's too well-timed to be a coincidence. It was clearly made in response to our smoke." [Y/n] muttered.
"You mean...?" Yuzuriha said.
"Yeah. This is exhilarating. There's someone else in this stone world." Senku said with a smirk.
"More people?" Taiju questioned.
"We have to finish putting out this fire." Yuzuriha said.
"Yeah, you're right!" Taiju said.
"No, hang on! As far as they know, that explosion could have been from the volcano. We need to signal them even more before they leave." Senku said with a slightly nervously expression.
"I see!" Taiju said.
"But... Tsukasa-san..." [Y/n] muttered.
"We'll be doing him the courtesy of letting him know where we are." Senku said and smirked.
'The least logical part of me, my gut, is talking to me. If we start a fire now... Which do I choose? Safety? The future?'
"Senku, there are many mountains around here. Don't do this." [Y/n] begged him, but Senku stared out at the smoke signal.
"What do we do, Senku? Put it out or light it?" Taiju asked.
"Light it! Fire the smoke signal!" Senku announced.
"What?!" [Y/n] question while looking at Senku with a terrified expression.
Senku placed both of his hands on [Y/n]'s shoulders. "Trust me, [Y/n]." He said, and she stared into his deep red eyes.
[Y/n] took a breath and nodded. "I trust you, Senku." She said. Senku and Taiju used gunpowder to light the flames.
"We're running out of gunpowder. Throw in anything thing that'll burn!" Senku ordered.
"Hang on! I'll go get some wood!" Taiju said while running away with Yuzuriha.
[Y/n] and Senku sat in silence. He knew that [Y/n] didn't agree with lighting the fire, but could you blame her? There was a superhuman after them. They sat around the fire while Inosuke curled next to [Y/n].
"[Y/n]..."
"No, Senku. I said I trust you. There's no need to reconcile with me." [Y/n] said, and her eyes widened in terror as she covered her mouth to hide the gasping noise the came from her mouth.
[Y/n] trembled as she witnessed Tsukasa holding Yuzuriha and holding a spear to her throat. Senku chuckled.
"'If weapons of science enter the scene, I won't be the most powerful anymore.' You look like you're about to throw a tantrum, Tsukasa." Senku said with a smirk.
"Hm. You could put it that way. If you make weapons of science and revive the older generations, they'll begin fighting over established interests, and we'll be right back in a tainted world. I don't mind getting my hands dirty in order to stop that." Tsukasa said while glaring.
"So now you have to kill the Science Man Senku, huh? America would be moved to tears by your merciful death sentence." Senku said with a chuckle.
"Yeah. But first, would you mind giving me the recipe for the petrification revival fluid?" Tsukasa asked and held the spear closer to Yuzuriha's neck.
"Sorry, but I'm not as merciful as you are. I can only look at things logically. I don't care one millimeter what you do with that woman. There's [Y/n] and plenty of other-" Senku said, and Tsukasa spun around, cutting Yuzuriha's hair.
"Yuzuriha!" [Y/n] called and run closer to them.
"[Y/n]!" Senku went to grab her wrist, but she was too fast. He should have anticipated that [Y/n] would act on her emotion instead of thinking logically. Tsukasa smirked and pushed Yuzuriha aside and grabbed [Y/n].
"Don't try to negotiate, Senku. You never buried Yuzuriha. Your best move would have been to bury Yuzuriha somewhere far away while she was petrified. That way, she's never been taken hostage, and [Y/n] wouldn't act on her emotion. There's no way you couldn't have thought of something even I did. But you didn't do it. Was it for Taiju? Or for Yuzuriha? No, it was for both of them." Tsukasa said and squeezed [Y/n]'s wrist, making her wince in pain.
"You call yourself logical, but you have friends that are precious to you. I have plenty of admirers, but I have no one I'd call precious. That's why I win, Senku." Tsukasa continued.
The baby boar squealed as he tugged on Tsukasa's clothes in order to stop Tsukasa from hurting [Y/n]. Tsukasa glared and kicked the boar aside.
"Inosuke!" [Y/n] yelled as the boar flew, and Senku caught him then gently set Inosuke on the ground.
[Y/n] a literally shaking in fear. Despite that, she gathered up the strength to speak to Senku. "D-Don't tell him, Senku." Her voice waivered and held the spear up to her throat while Senku's eyes widen with fear, "As long as he doesn't have the recipe, Tsukasa-san can't kill you. As I said, I'm useless without you. You have to survive to secure everyone's future."
The fear in her voice broke Senku's heart.
But he smirked and put his hands on his hips. "The revival fluid is a compound of nitric acid and alcohol. Filter the miracle water from the cave and mix it with alcohol that's been distilled up to as close as 96% as you can get. The ratio is 30% miracle water and 70% alcohol. If you're off by so much as a few percents, the reaction won't happen, so fine-tune it using a petrified swallow feather." Senku explained, and [Y/n]'s eyes widened while Yuzuriha's eyes filled with tears.
Tsukasa pulled [Y/n] closer to him and smiled. "Thank you, Senku. I no longer have reason to let you live." Tsukasa said and pushed [Y/n] aside. She was caught by Yuzuiha.
"Senku!" [Y/n] called, but Yuzuriha held her back.
"No, [Y/n]! It's too dangerous." Yuzuriha said, but that still didn't stop [Y/n] from trying to get away. Tsukasa stood in front of Senku.
"If I let you live, you would let civilization develop. Will you promise that you won't do that?" Tsukasa questioned, and Senku chuckled.
"What the hell are you talking about? Why would I ever keep a promise like-"
"No, you would never lie. Not to science. Will you promise here and now, for all of eternity, that you'll abandon science? If you do, I won't have to kill you, Senku." Tsukasa said with a pained look on his face.
[Y/n] trembled. There's not a chance that Senku would abandon science. It's been like that for as long as [Y/n] could remember.
｡･:*:･ﾟ★｡･:*:･ﾟ☆
"All right, next is Senku-kun."
"I'm going to space." Little Senku said as he stood up in class. The whole class was in shock while [Y/n] looked at him with admiration. She loved science even at a young age, especially astronomy.
"An astronaut! That's a great dream. Well, when you grow up..."
"No, I'm going immediately." Which shocked the teacher. Senku chuckled.
"Then again, I'm just a kid who doesn't know the first thing about science." Senku muttered to himself. Little [Y/n] stood from her desk.
"I-Ishigami-kun..." [Y/n] called out to him as he made his way to the hall.
Senku stopped and turned to her. "Who are you?" He asked and looked at the girl with the small twinkle in her eye.
"I am Sakurai [Y/n]. Please, let me accompany you to space with you." [Y/n] pleaded and pulled something out of her school bag, "My mother bought these for me. I'm sure it could help us." She continued while holding out a basic high school science textbook and an astronomy textbook.
Senku's eyes widened. "What kind of preschooler are you?!" He questioned and pointed her forehead, "You must have a large brain."
[Y/n] smiled a little, and Senku blushed slightly."My body is not fully developed to know how large my brain is. The information I've learned is all in textbooks at my home." [Y/n] continued, and Senku rubbed the back of his head.
"You talk pretty weirdly, but I could use a genius lab partner." Senku said, and [Y/n] smiled more. "Let's go to the library." Senku led the way.
"Okay!" She cheered, following behind him.
Weeks went by, and the two continued their mission to go to space. [Y/n] placed a sheet of paper in the grass while Senku held a magnifying glass up to the sun. Both of them wore matching white lab coats that Senku's dad bought for them.
"You can burn things with the point of light from a magnifying glass." Senku said while [Y/n] nodded and wrote notes in a little journal she had. The next day, the two started a new experiment. Senku and [Y/n] sat behind protective glass with goggles to cover their eyes.
"Sand iron and aluminum foil are awesome." Senku said with a smirk.
"The frying pan is melting from the thermite reaction." [Y/n] commented while writing in her journal. The next day, they worked on the injector for their spaceship.
"The liquid oxygen for the injector boils off ten billion percent at a normal temperature, and it freezes when it's too cold." Senku muttered, and [Y/n] nodded while writing down the temperatures and notes about the experiment.
"We'll have to keep working on the ethanol until we switch to kerosene." [Y/n] said, and Senku nodded in agreement. The two talked over a few other things until they noticed three middle schoolers stomping on their device.
"Oh no!" [Y/n] said, rushed over to them to convince them to stop, but she was pushed aside. This angered Senku until a brown-haired boy suddenly charged at them and blocked their attacks from the device.
"Are you okay, [Y/n]?" Senku asked while helping the girl up. She was a bit shaken up. "That was terrifying." [Y/n] muttered and squeezed Senku's hand.
Senku had an evil smirk. "I'll make them pay." He muttered, and the next day, [Y/n] saw Senku with a weird device that shot electricity at the bullies.
[Y/n] was amazed. "Senku! I made the ablator!" [Y/n] called while walking towards him, and Senku set his contraption down. [Y/n] handed the device to Senku.
"What's that?" The boy from earlier, who they learned was Taiju, asked.
"It's an ablator. The chamber will burn out if we don't use it." Senku explained. The ablator began to shine, and Senku threw it in the air then grabbed [Y/n]'s hand as the three children ran away. The ablator combusted.
Thanks to Taiju's help, [Y/n] and Senku were ready to test the prototype of their spaceship, but it exploded. Back at Senku's apartment, [Y/n] and Senku discussed what they needed to do while Taiju was there for the manpower.
"We'll use old Yagi antenna for the receiver." Senku said while [Y/n] nodded.
"I have an old television we can use." [Y/n] said when suddenly Taiju opened something that exploded.
Years went on and the friends entered middle school. [Y/n] and Senku stood in an empty club room that they turned into the science club.
"Senku! [Y/n]! You said you'd try it with a light payload, right? I had Ogawa Yuzuriha-san from the crafts club make us four passengers." Taiju said, and Yuzuriha pulled out four handmade dolls. [Y/n] was impressed.
"It's seriously embarrassing, having a doll of myself. What are you even using these for?" Yuzuriha asked.
"Cute..." [Y/n] muttered while picking up the doll version of her.
After school that day, Senku, [Y/n], Taiju and Yuzuriha went to the usual hill that [Y/n] and Senku would test their experiments. Senku placed the dolls inside of the rocket, and Tajiu went to position it.
Once everyone was a safe distance away, Senku and [Y/n] looked at each other then nodded. Senku and [Y/n] pressed the red launch button together.
They watched as the S[Y] ship flew into the air then exploded.
"It combusted at a high altitude." [Y/n] muttered with staring at her laptop that had her name.
"It failed again?!" Taiju questioned.
"Not entirely." Senku said and held up the laptop with his name and turned it around.
There was a satellite image of their dolls floating in Eath's orbit. Taiju and Yuzuriha stared at the laptop in amazement.
｡･:*:･ﾟ★｡･:*:･ﾟ☆
Science was the reason [Y/n] and Senku met. There's no chance Senku would give that up.
"Senku, I'd rather not kill you if I can help it. I'll ask you again. Will you promise me, here and now, that you'll abandon science?" Tsukasa asked, and Senku smiled, sadly.
"I can't do that." He said, and [Y/n] gasped. Tsukasa took a deep breath.
"I thought that would be your answer." Tsukasa said, and Senku chuckled.
"What are you babbling about? You were going to kill me at some point, no matter how I'd answer. To be on the safe side." Senku said and cracked his neck, "Do it in one blow. Making me bleed out forever wouldn't be logical for either of us."
"Don't worry. I'll bust your cervical never in a single blow. You'll be knocked unconscious instantly, then you'll die. I won't make you suffer. I promise not to miss." Tsukasa said, "Senku, if we'd met 3,700 years ago... If we met before this planet became a stone world... You may have been my first friend."
"Maybe." Senku said, but all he could see was Tsukasa confessing his love for [Y/n], and Senku would be out of her life. Senku hated that thought. Tsukasa slowly walked closer to Senku. With one swift move, Tsukasa hit Senku in his neck. [Y/n]'s eyes widened in pure shock and terror.
"SENKU!!!"