Amakusa days: cursed life in a different world

[Lifkinthetroll]

Chapter one.



















​

Having been born in this world some 16 years ago, one might expect Amakusa Renji to well versed and experienced in the basic rules and regulations one has to follow. And he did, Unfortunately for those watching, while Renji had been alive for 16, nearly 17, years, I had not, and i did not, in fact, know those rules and regulations. I had just woken up in Renji's body hours ago and was still processing all his memories. I, one Ray Aberdeen, was fatally under-prepared and untrained for jujutsu high and all its weirdness.



Sigh let me go back a little, hello, I'm ray and I died. It wasn't anything special, or even something particularly telling, I had cancer, stage 4, in the lung. I wouldn't have lived past my 20th​ birthday, so I asked to be let go, I didn't want to prolong my suffering any longer then I had to. So you can imagine my surprise when I opened my eyes and I wasn't in a hospital or even in heaven, I was in a small dingy apartment in Kyoto. Barely less then an hours walk from jujutsu tech.



I found out then (through a typical memory-type brain blast) that I was now Amakusa Renji and that I was a jujutsu sorcerer. Renji came from a small jujutsu clan that swore servitude to the gojo clan some six generations back. The inherited technique of the Amakusa clan was called synthesis, it allowed the user to fabricate skills and items using cursed energy. A more detailed explanation:

Spoiler: technique explanation

spoilers ahead! Cursed Technique: synthesis

The user can permanently fabricate techniques (skills) and material objects from cursed energy. These creations become part of their arsenal for life, requiring no external teaching, training, or crafting tools — only cursed energy, imagination, and understanding. However, the cost of creation is directly proportional to the user's comprehension of what they're fabricating. The less they know about what they're trying to create, the more cursed energy it costs, and the higher the chance of failure. This makes the technique both powerful and strategic — rewarding deep study, practice, and calculated risk.

1. Skill Fabrication (技の創造 - Waza no Sōzō)

"To give an idea form."

The user can create permanent combat skills, such as martial arts styles, weapon techniques, body movement systems, or mental techniques. Each skill is like a sealed scroll of instinct and execution — burned into the user's mind and body once created. These are not copied from others — they are independently synthesized based on the user's interpretation or experience.

Skill Creation Cost Depends On:

Direct experience: A technique born from something the user has done before costs the least.

Observation: Seeing something similar in battle or training lowers cost.

Theoretical knowledge: Reading about a style or movement gives a baseline.

Pure imagination: Creating something entirely new with no reference point costs an extreme amount of cursed energy and carries high failure risk.

2. Object Fabrication (物の創造 - Mono no Sōzō)

The user can forge physical objects from cursed energy — weapons, tools, armor, equipment — by visualizing both form and purpose. These items are tangible and permanent once created. they can have innate techniques like true cursed tools but it is much more expensive, they can, however, be designed with clever mechanics or cursed traits, which costs less

Object Creation Cost Depends On:

Technical understanding: Knowing how a weapon functions lowers energy cost.

Design complexity: The more moving parts or cursed traits, the more cursed energy it takes.

Combat compatibility: Items made to complement an existing skill cost less than totally unrelated ones.

Limitations & Weaknesses:

High Initial Cost: Once a skill or item is created, it's permanent — but the creation cost is irreversible and cannot be refunded.

Mental Strain: Creating complex skills or combinations without preparation risks overloading the user's mind (nosebleeds, vertigo, or temporary seizures).

Balance Required: Creating too many skills or weapons at once spreads the user too thin — forcing them to prioritize synergy over quantity.

No Skill Stealing: Cannot duplicate techniques used by others unless the user understands them in principle.

with this technique the amakusa clan had stood a vassals to the gojo's for quite some time. though in reality they were little more then tool makers and low grade foot solders. More importantly that, Renji wasn't really Renji anymore and was more then a little lost on what to do and how to act. Now, hours after waking up, he was in class with his fellow second years trying his best not to make a scene. Too bad Maki caught on quick. "Oi, Amakusa. Why are you being so stiff?" Renji stiffens. 'crap' he thought 'how did she figure it out' "w-what do you mean Maki-san?" Maki's eyes narrow. "well for one, you never call me san, always chan even when I tell you to stop." 'damn, damn damn damn.' He repeated in his head as he searched his mind for memories regarding Maki and his other classmates. She was right it turned out. Renji had a major crush on Maki and very poor boundaries. "w-well I figured if calling you chan all the time, even when you asked me not to, wasn't getting me anywhere, it might be time to change how I did things, starting with being more respectful to you, maki-san." 'There, that might work for-' his thoughts were cut short when he noticed the focused and confused looks of maki and his other classmates. "….what?" maki sighed and shook her head before her, panda and inumaki all went back to ignoring him. 'this sucks.' He thought as he laid his head on his desk and waited for class to start.

---

It took almost another hour for gojo to show up. During which he processed the rest of Renji's memories. Suffice to say he had botched his Renji impression earlier. 'Too late now I guess.' As it turned out Renji was a lot like naoya zenin, jjk's very own misogynist, just less…. Vocal about his beliefs. Which only meant it would be harder to gain respect and social power in this life. these many factors, all of which were bad for him, combined into a situation which only lowered his ability to deal with people, specifically, people like gojo. "Morning class!" was the first thing I heard [the honored one] say. While I would have loved to say the seeing gojo for the first time was some life changing experience, or that I was intimidated by his very presence, it wasn't and I wasn't. gojo felt normal, he might not have looked or acted normal, but, to my still growing sensory ability? He just felt like a particularly strong sorcerer.



Thankfully by the time gojo walked in I had absorbed all of Renji's memory and persona and there wasn't much difference between us besides what I let out. I was used to masking pain and negative emotion due to my past with cancer so I put forth a cold front for most of class, only letting anything through in moments when I thought the original Renji might have. For almost two hours I sat there and tried to project an aura of 'I look down on women.' To my eternal horror I think it might've worked. I'll never recover.



After class it was P.E which meant three hours of mandated exercise and trying to avoid my classmates. As I tried my best to stay under the radar and my eyes on the ground I found out that my new body was actually pretty strong. I was able to do plenty of pushups and sit-ups before I was worn out.

Once I had done the required exercise I wandered off, just for a little to get a feel for my cursed technique. While Synthesis was simple in thought it was complex in practice. With a bit of effort (and muscle memory) a had a simple steel sword in my hand. After Swinging it few times to get a feel for it I set it down and did a quick mental check to feel what skills Renji had already synthesized, I was shocked to feel exactly two. The first was amakusa martial arts, the second? social skills. he had used his family's vaunted technique to get better at talking to people, it wasn't like i didn't understand, it was just... it hadnt worked which just made it sad.


I sighed heavily and got to work producing household skills like cooking and cleaning. Then other mundane skills that I had in my past life. Then I moved on to skills I had gained through training, my experience in my past life letting me cut down the cost of producing the skills by a lot. Finally I converted Renji's experience into skills. There weren't many but it did net me [sword wielding], [archery], [cursed energy manipulation], and [reinforcement]. He sighed and looked into what other skills he could fabricate with his current reserves and was shocked to find that if he paid his full reserves now, waited a full day, and poured his entire reserves into it again that he could fabricate [cursed speech] inumaki's inherited technique. I put a bit of thought into it, divided the portions to spread out his reserves and payments over a week rather than two days, and mentally started the process of fabricating the technique. Instantly I lost five/eighths of my cursed energy reserves to the skill. Letting out a wheezing breath I sat down and let myself recover.



After about half an hour, I headed back to the school and 'ran into' inumaki. "hey. Can I talk to you?" inumaki looked over and his face fell flat at the sight of me, he stopped for a second before reluctantly saying "shake." I walked over and stood a few feet away. "I just wanted to say a few things and I figured you were the most likely to listen." I took a deep breath and looked him in the eye "First, I really am sorry for the way I acted in the past. Mostly it was due to the way I was raised, but I'll admit that I never bothered to try to get to know any of you guys. I was given a lesson in respect and kindness not too long ago and I've been trying to decide what to do with myself since. I chose to change and become better. That starts with you panda-san and maki-san. I hope you'll give me a second chance." I looked away and tried not to die of cringe at the word vomit that I had just spewed, unfortunately I had something else to say.



"second, I recently figured out a new way to use my cursed technique which is very similar to okkotsu-san's copying technique. The first technique I decided to copy was yours. I wanted you to know so you didn't freak-out the first time you saw me use it." Inumaki's eyes widened and then narrowed rapidly as he processed what I said. At first it seemed he would call me on it, ask me to prove it, then he seemed resigned, tired. "shake" was all he said before walking off. I stood there for a moment, surprised, then I shrugged and turned to go home. Just like inumaki I was also tired and wanted to sleep. Today sucked, maybe tomorrow would be better……. Yeah right, like that would ever happen.

---

morning: the next day.

"iiiiiiittt'sss time for missions!" gojo announced "who's ready!?"

I could only say one thing. "crap"

 

[Lifkinthetroll]

this is my sfw version of this story. i'll try not to compromise the story to much in editing. thanks for reading.