(Not edited)

"ha ha... You really did me a favour. Washing long hair is a pain in the stone world, now that it's short though..."

Yuzuriha took a massive gulp as she said this. The blade was but millimeters away from her throat. The more she thought about the events, the more and more willing she was to sacrafice herself.

"Don't tell him Senku. As long as he doesn't know the revival fluid recipe... Tsukasa can't kill you."

The spear was now poking her skin.

"I don't matter. Not really. But you Senku... If there's any hope for the future, for anyone... You're the one who can't die."

Tears were welling in her eyes, her whole body shook. She was terrified of dying, yet it was the only way. However Tsukasa was right, Senku did have a soft spot for his friends.

"The revival fluid.. is a solution of nitric acid and alcohol! After filtering the miracle fluid from the cave, mix it with nearly pure 96% distilled alcohol. Three parts to miracle fluid to seven parts alcohol. The reaction won't occur if you're even a tiny bit off. You can adjust the proportions while testing on a petrified swallows feather."

Senku's voice was defeated as Yuzuriha wept. The only thing keeping her friend alive was gone. All Tsukasa did was smile and push the girl away.

"Thank you. Senku. Now I have no reason to let you keep living..."

(Y/n) and Taiju were still gathering sticks for the smoke signal. (Y/n) noticed the three smoke signals in the distance, which she pointed out to Taiju.

"Taji-kun look! There's three smoke trails in response to our three explosions!"

"WOAH THAT'S SO COOL! THAT MUST MEAN SOMEONE'S OUT THERE!"

the (h/c) girl nodded happily, before dread hit her.

"Hold on.... It's been 3 days and a bit at this point, Tsu-kun probably left for us a few hours after us probably... And it's been a few hours so that must mean.."

Before (y/n) could finish the two heard a noise in the distance. It sounded like a voice.

"TAIJU! (Y/N)!"

the two immediately recognises it as Yuzuriha's.

"SHIT (Y/N) WE HAVE TO GO BACK NOW!"

The two were sprinting as fast as their muscles could possibly carry them.

"If I let you live... You'd go on to develop civilization. So promise me you won't do that."

"Heh heh heh. What're you talking about? I could promise you anything just to live..."

"No. You're no liar. Not when it comes to science. So just swear on your life that, from now until forever, you'll stop trying to create a scientific civilization for mankind.

Do that, Senku... And I won't have to kill you."

Tsukasa had a sympathetic smile, well as sympathetic as it could get for a murderer. It was obvious to Senku that Tsukasa didn't want to kill him. But at the same time Tsukasa was willing to do anything to make his dream a reality. Before either of the two had said anything, Senku thought. He thought about all his life that had led up to this.

"I'm going to space!"

Senku said in the classroom, a bit over 3,700 years ago.

"An astronaut! What a wonderful job for when you're older."

His teacher said.

"No way that's way too long! I'm going much sooner than that."

Most of the kids looked at Senku weird after saying that, but he couldn't care less. He just wanted to go home and start his research. He started with talking to his dad.

"Kukuku I don't even know the first thing about science. But you gotta start from square one."

His dad sweated a bit at this, but that was his son for him. Senku then started going to the library everyday, the older people looked at him weird, while he had stacks of science books surrounding him. That was until he met a girl in there.

"Oi why do you have so many science books?"

She asked the young onion head boy. He looked up to see a girl with (h/c) hair and (e/c) eyes. Who was also surrounded by books.

"I could ask the same to you!"

"Well I'm going to become a doctor really young! What kind of scientist do you want to be?"

She asked pointing to all his books which were all about different science subjects.

"All I want to do is go to space. But I want to know all the sciences. I'm Senku by the way."

"Pleasure to meet you Senku, I'm (y/n)!"

After that day the two would often hang out, (y/n) would teach him about medicine and surgeries, while he'd teach her about everything in-between. The two would often have 'playdates' which were mostly just study sessions at Senku's house, which is where Byakuya saw how serious his son was about science.

A few weeks before Christmas Byakuya made the decision to sell his car.

"Your old dad won't be much help. But if you're serious about this Senku, there's nothing you can't accomplish with science and diligence!"

Senku's dad said to him, on Christmas day his room was filled with all kinds of science things, even a telescope! Senku was overjoyed! He would experiment every day, with or without (y/n). One time the two of them met another boy, called Taiju. He saved Senku's flame thrower from a bunch of middle school boys.

"TAIJU YOU'RE SUCH A BRUTE! IT'S SO COOL!!"

(Y/n) yelled to her friend, as she fixed his wounds. Taiju gave a bashful smile to the girl.

One time at Senku's house, Taiju caused a massive explosion. Which almost got Byakuya and Senku evicted! However no matter what the three were still friends.

Years later they were all in middle school. Senku's experiments were getting wild and wilder, his dream of getting to the moon was getting closer and closer. While (y/n) got closer to being a doctor. And Taiju got closer to a girl, a girl named Yuzuriha.

"SENKU! (Y/N)!"

Taiju yelled, running into the science club.

"SENKU, YOU SAID WE COULD LOAD THIS WITH LIGHT CARGO RIGHT?? I ASKED YUZURIHA OGAWA FROM THE ARTS AND CRAFT CLUB AND SHE MADE THESE FOUR LITTLE PASSENGERS FOR US!"

Yuzuriha's face was beet red.

"I know it's a little embarrasing that I'm into doll making..."

"WHAT ARE YOU TALKING ABOUT, THESE ARE SO CUTE AND COOL, I LOVE THE ONE YOU DID OF ME, I'M (Y/N) BY THE WAY! CAN I CALL YOU YUYU-CHAN?"

(Y/n)'s eyes were glued to the doll of her, it was just way too cute.

"Haha thank you (y/n)-chan... And sure! But want are these all for??"

The four went down this small little nature trail path, Taiju couldn't stop staring at Yuzuriha, which caused (y/n) to tease him a little. The two eventually reached a rocket, which the dolls were loaded into. Senku set it off, only for it to blow up.

"ANOTHER FAILURE?!"

Taiju said in defeat.

"Heh heh heh... Not exactly. I only got one transmission but it's a good one!"

Senku showed the three the screen, and they saw all their little doll selves in the atmosphere... All four of them floating together.

Senku's thinking stopped there. It was some of the best moments in his life.

"Senku. I won't have to kill you if I don't have to, you're a good person. And (y/n) really likes you as well. So swear to me, here and now. Swear that you'll give up science."

Tsukasa said, he wasn't smiling anymore, but Senku was.

"That's the only thing I could never do."

Tsukasa took a deep breath.

"Right, I knew that'd be your answer."

"Heh heh heh, don't give me that crap, you would've killed me sooner or later."

Senku said, still a smug smile on his face.

"Perhaps, perhaps not."

"Whatever, just try to finish me in one hit. It wouldn't be logical to have blood gushing everywhere."

"Don't worry. I'll snap your cervical plexus in one blow. You'll lose consciousness and die instantly. I won't make you suffer. And I won't miss."

Tsukasa took his lion coat off. It was a somber moment for the two. Yet they were both smiling. Yuzuriha was powerless to do anything.

"Senku. If only we had met 3700 years sooner. If we'd met before this planet became a stone world. You might of been my second friend ever."

"Maybe. But don't worry, you'll always have one friend."

Tsukasa have Senku one last smile, before dashing towards him. Hitting him in one swoop. Just as Taiju and (y/n) got there.

(Y/n) couldn't say anything, she just screamed and ran to his lifeless body. She checked every possible place where a pulse could be read. Every place where she could feel his breath. Every place she could hear heart beat. But nothing
Nothing
Nothing
And nothing.

(Y/n)'s whole world turned upside down, she couldn't hear anything, her throat hurt so much, she couldn't scream. All she could do was put her friends lifeless body on the ground. In the corner of her eye she watched Yuzuriha throw the black sand at Tsukasa. The utter force that happened made an explosion, which separated her from Yuzuriha and Taiju.

Before she knew it, they ran away with the body. Leaving her behind with Tsukasa. Tsukasa thought he was alone. Until he heard the soft cries from (y/n). He looked at her with the utmost pity. He lightly touched her arm, waiting for her reaction. But she didn't do anything. She didn't flinch, pull away. She just let it happen. So he brought her into a hug.

"I'm sorry. I'm so sorry, I didn't want to hurt you like this. But I had to. It was for the best."

All (y/n) could do was scream into him, and hit his chest.

"Bring him back! Please Tsukasa, please, please! Undo it, bring him back please. I'll do anything! Please.... I just want him back."

She said between sobs. All he could do was look down at her. She looked so meek, so broken.

"I'm sorry."

"Please.... Why him. I know the formula as well! So why not get rid of me as well!"

(Y/n) yelled, looking up at him. He let go of her.

"Don't be so dumb (y/n), you know exactly why."

"Say it! Don't be cryptic I know we're friends but why, couldn't you find it in your heart to not kill him?!"

Tsukasa was quite for a bit, just looking down at the girl.

"I don't think I have to say why I wouldn't kill my only friend, who was also working on a cure for my sister. The answer seems pretty obvious doesn't it?"

"Just say it if it's so obvious!"

(Y/n) tone was so agreesive and this point, it's the most angry that Tsukasa has ever seen her.

"Because I love you. And I Know that no matter what I do, deep down you will still have some love for me in any way. Romantically or platonically. You could never hate me. Sure you might not like me for a bit but in the end you'll realize that all you have is me. You're not a threat like Senku, because Senku would kill me. You on the other hand... You couldn't kill anyone."

Tsukasa spoke as he cupped her cheek. He knew it was wrong of him to do this to her. He knew that she was going to run away for a bit. But he was right. She doesn't know where Taiju or Yuzuriha are. And Senku is dead, so she really is alone.

"Listen (y/n) I'll give you a choice. Either you go with me to my new kingdom, or you run away for a bit. We could meet up in a year or so? How does that sound?"

(Y/n) didn't say anything, she just backed away out of his grasp and left.

She was all alone.