----------(Hayate's Diary)----------
Entry 1:
It's been a month since master took me in, and I have to admit, the training he's been putting me through is a lot harder than I thought it would be. After asking for my age, he created a plan to prepare my body for later, or so he said. He's also been making me eat a lot of food, so it's easy to guess what he's trying to do.
After living together for a month, master has dubbed me a genius because of how quickly I've picked up writing and reading. I think my enhanced sense of sight helped a lot with that, though, since I've noticed that it helps me memorize things more easily. I'm good enough to write this diary, so that's good, even though master has to correct a couple mistakes here and there.
Tomorrow I'll be starting strength training, which apparently is going to be a lot harder than just running around the house. I hope it all turns out well.
----------(Switch)----------
Entry 17:
It's now been almost half a year since master took me in. The seasons have changed, and the mountain is now covered in snow, which gave master the brilliant idea to create even more sadistic forms of training.
Never did I think that sitting on the snow, almost naked, while vibrating to keep myself warm, would be an exercise, but here we are. I've gotten a lot stronger since I first arrived here. It's gotten to the point where I can carry master on my shoulders and run around for a good while without tiring.
Master said that he'll start teaching me how to breathe soon. He's been talking about this for a long time so I can't help myself from getting excited.
On another note, my Japanese has improved tremendously, and I can write this diary without master having to go over it to fix any mistakes.
I can't wait for the next six months to pass, so I can start with real training.
----------(Switch)----------
Entry 38:
It's been a year since master took me in, and I have just turned eight. Master asked me about my age back when he first bought me and I remembered being seven at the time but not the exact day of my birthday. He decided that my birthday would be the day of our meeting and I couldn't help but agree.
Today was great because master took me to the village at the foot of the mountain to celebrate. He even got me a gift, a haori similar to his but electric blue in color, with the triangles being black. I liked it a lot, and even though I know I'm probably going to outgrow it, I still appreciated the gesture.
Tomorrow will be when my training in breathing begins, and I can't help but want to start right away. Master said that my body was naturally attuned to these breathing exercises and also said that my enhanced eyesight would be of great help.
I hope to live up to his expectations.
----------(Switch)----------
Entry Alpha:
I'm writing this in English with the hopes that if anyone were to find this diary, no one would be capable of reading it. This past year has changed me a lot, and while it is scary to change so much in such a short time, I couldn't be happier.
Gramps, despite being a very tough teacher, still takes care of me and makes sure I rest and don't overwork myself. I have noticed that humans in this universe are innately stronger than regular humans. I always thought it was because of breathing styles, but in reality, the human body here is a lot more flexible and miles stronger compared to earth's. It explains how Inosuke did that weird moving-around-his-organs thing in the Entertainment District arc.
On another note, I've finally sorted out this body, or rather my body's memories. Even though my previous memories, and therefore my previous consciousness, weren't here at the beginning, I still recognize the experiences as mine. I grew up in a family of farmers that were very poor. They had a lot of children, so they had to sell some to get money and lessen the number of mouths to feed. My distinct appearance made me the money maker so I was sold. During my stay with Nagumo, he used to beat me and make me pickpocket strangers in the entertainment district, which just got people to beat me more, so I can't really call it a nice stay now can I.
The only reason I'm able to write about this calmly is Gramps. When I first processed the emotions, I was enraged. I wanted to get some form of payback on Nagumo. I wanted to go back and see my family, but after having a year to think it through, an entire year in which I learned, trained, ate generously, and so much more, I've come to terms with it. No point in doing something like that when there are much bigger problems on the horizon.
I'm both my old self and Hayate Raikiri, and I'll do my best to merge the positive traits of both so I can help everyone who has suffered reach an ideal ending, as is my deal.
Tomorrow will be the first day of actual training. Time to take the next step. Let's see if I can handle it.
----------(3rd POV: Hayate)----------
"Masteeerrrrr~ Do we really have to go up to the top?"
"Stop whining, brat! Just keep going. Weren't you so excited this morning about learning breathing techniques?"
"But..."
Before Hayate could continue his sentence, he felt a glare at the back of his head, so he just sighed and stayed silent.
He had woken up in the morning full of energy, ready to finally learn the breathing techniques that would allow him to become a demon slayer, only for Jigoro to take him by the hand and drag him towards the summit of the mountain.
"Can I at least know why we're going there?"
"Eh, why not? To learn the breathing techniques I've been talking about, you need to strengthen your lungs. The lack of air and the pressure atop the mountain will make for the perfect training grounds."
"If you say so, master."
He received a hit to the knee for his flippant response.
"HHisss...Master—"
"Don't sass me, brat!"
"But I wasn't—"
A raised cane from Jigoro was enough for him to shut up.
The old man kept walking behind his disciple with a thoughtful look on his face before he made up his mind and began to speak.
"Hayate, have you ever wondered why I've been training you so hard?"
The question gave the boy pause for a moment before he responded, his tone full of sincerity and trust.
"I'm guessing it's about the demon slayer corps you mentioned when you first bought me. It sounds scary, master, extremely so. But... you've done a lot to help me and I'm sure you want the best for me, so I'll listen to you."
Jigoro put a hand on his chest at the critical attack but regained his bearings quickly before smiling at his disciple.
"Your trust in me means a lot, Hayate. Don't worry, you'll understand when we get to the top. I'll do my best to explain."
Hayate simply gave a nod that he knew his master could spot even from behind him and continued the track upwards.
By the time they had made it to the top, the sun had risen to its peak and was shining brightly, illuminating the lying figure of Hayate. The boy was stuck to the ground and was breathing heavily, trying to keep himself conscious so he could listen to his master's lecture and instructions.
"You did good, kid. Now just stay there and breathe. I'll talk and you listen, you hear?"
The boy raised a trembling hand in agreement before letting it drop once more.
Jigoro nodded at the motion before he found a rock flat enough for him to sit on. He stared at his disciple's exhausted form and couldn't help but smile. He was once again mentally patting himself on the back for finding such a good successor.
"A year ago, when I introduced myself to you, I called myself a former Hashira and a member of the Demon Slayer Corps. You guessed right in saying that the Demon Slayer Corps is terrifying, and the reason for that is our mission, our duty. For a thousand years, a monster by the name of Muzan Kibutsuji has roamed the land of Japan, turning humans into creatures of nightmare. Demons, beings that rely on human flesh to survive and get stronger."
Hayate, despite already knowing most of this from his previous memories, kept his ears open, listening closely to his master's words. It was novel to hear this from the perspective of someone that lived through this.
"Sadly for us, those bastards have the advantage. They can regenerate from any wound and are naturally stronger. Some of the strong ones even have spells known as Blood Demon Arts that they use to cause even more damage. Their only weakness is the sun, but trying to keep a demon trapped until dawn is almost impossible. Despite all of our weaknesses compared to those monsters, we haven't allowed it to stop us. We never will.
The Demon Slayer Corps has existed for generations, and under the leadership of the Ubuyashiki clan, we have found ways to fight against them. We will continue to fight until none of us remains. We will use our swords to protect humanity, to make sure that Muzan Kibutsuji is killed. As long as even one of us exists, the demon slayer crops will live on until it accomplishes it's mission and rids the world of that devil once and for all."
Hayate gulped as he felt his master's passion and will. It was inspiring and at the same time intimidating. The will that the man possessed. This desire to destroy Muzan and eradicate all demons.
"If you choose to follow my path, I will teach you all that I know so that you can rise above the rest and lead the Corps on their mission. So you can become a pillar, just like I was. It's time for you to make a choice, Hayate. Will you carry on the Corps' mission?"
Hayate stayed silent for a few moments. It was only now, when it was shoved so bluntly in his face, that he realized how... different things were. He couldn't accept just for the sake of his deal with God. Half-assing things wouldn't work. Not for this.
He needed to actually want it. And did he?
He forced his exhausted body to sit up so he could face his teacher and look him right in the eyes.
"Master... I don't know about these demon things. I believe you, of course, but I don't know if I have the same conviction you have. Despite that, I want to try if you'd let me."
Jigoro stared for a few moments, searching for any signs of hesitation before letting out a laugh.
"HAHA. Good. You've done well, brat! Now get up, time to train."
"Master?"
"I said up, dammit! Let's get to it."
That was the beginning of Hayate's years of training hell.
{A/N: I feel this was a good chapter overall. The diary thing was a way for Hayate to record his thoughts and a shout out to Tanjiro since he did the same thing while training with Urokodaki. The speech I felt was necessary because Hayate hasn't actually faced a demon, so he doesn't have the same desire as someone like Shinobu whose family was killed. This is the final chapter for the prologue if that's what you guys want to call it. The next batch of chapters will be training, some introduction to new characters from the canon, and more, so stay tuned.}