1,001 Ways to Keep My Senior Brother from Becoming a Ghost

[Next up: Little Kuai-sensei in JJK, My Senior Brother Is Still Being Tormented by His Golden Finger, is now open for bookmarking. The blurb is below. If you like it, please add it to your collection~]

[Main story complete, bonus chapters may drop at random]

Zenitsu died alongside his scum senior brother in the Infinity Castle. Even as he lay dying, he was still thinking about how despicable his senior brother was for abandoning him and Grandpa to become a demon. But when he opened his eyes again, he was still staring at that same hateful face.

During the fight with his senior brother, a little demon blood got into Zenitsu's brain, and he went dark. He grabbed his senior brother, who was only ten years old, and could think of nothing but how to stop him from becoming a demon.

The only reason his senior brother became a demon was that he had too much free time! Zenitsu decided to make sure his senior brother had plenty of trouble to deal with.

And so began Kaigaku's miserable life.

His senior brother had to accompany him to meals, to sword practice, and even to the damn bathroom, where they had to hold hands the whole way!

He called for his senior brother when he went to sleep, when he killed demons, and even when he wanted to go down the mountain to find a wife!

Under this relentless harassment, Kaigaku had no chance of becoming a demon. He didn't even get the chance to use the bathroom by himself!

Unable to stand Zenitsu's intense surveillance, Kaigaku secretly packed his things and tried to run away. But before he could even leave, he saw Zenitsu waiting at the door with his own things packed. Still half asleep, Zenitsu asked, "Senior Brother, where are we going in the middle of the night...?"

"Or," his gaze turned dangerous, "are you planning to leave me, Senior Brother?"

He was practically a demon himself!!

Kaigaku wanted to fight back, but Zenitsu, who had transmigrated from the Infinity Castle, was no one he could easily defeat. So the miserable Kaigaku could only train in swordsmanship every day, hoping to one day beat Zenitsu and regain his freedom.

But as he kept training, he somehow ended up in his junior brother's bed!!

Kaigaku covered the red marks on his increasingly well-developed chest, built up by all that daily sword practice, and wondered if something was wrong with the world.

In his last life, his senior brother had always rejected him and kept him at a distance. This time, Zenitsu had learned his lesson: even if his senior brother thought he was a creepy, obsessive guy who was into men, he would still stick to him!

To his surprise, sticking close to his senior brother unlocked all sorts of forms he'd never seen before: a tsundere young lady in a furisode kimono, a straightforward little kitten of a senior brother with pear blossoms, an adorable pointy-eared senior brother who could hide in a box, and a dashing Thunder Hashira senior brother!

Zenitsu covered his nosebleed, which was spurting everywhere because his senior brother was so beautiful and adorable. The brave get to enjoy the world first! Senior Brother!! Let me cling to you!!

It wasn't until he started dreaming about his senior brother, too, that Zenitsu realized something was off.

After coming back, Zenitsu thought it over and decided it was all because his senior brother had such a fierce-looking face.

The returned Zenitsu stared fiercely at his senior brother's fierce face, and the longer he looked, the more he thought his senior brother was really something.

I mean (lick lick lick), that face of Senior Brother's (lick lick lick), it's so good-looking. Who could've thought of it? (lick lick)

Senior Brother, isn't that just another kind of wife??

Zenitsu reluctantly (happily) threw himself into his senior brother's arms.

(Grandpa Kuwajima, both your disciples are gay!!!)

Content warnings:

1. This is a dark Zenitsu. It's roughly what you'd get if his sleeping and waking personalities merged, with a little added obsession with his senior brother. PS: Zenitsu's soul has been through a lot. First, his scummy senior brother's Blood Demon Art split it apart; then his senior brother's demon blood patched it up. Next, transmigrating through time strained and crushed it, then put it back together; the sun cracked it, and it got stitched back up again. So the Zenitsu in this story is pretty much Zenitsu: Remastered. Just treat the differences from canon as the parts that got squeezed out during time travel, okay? Thank you, thank you! (Please!)

2. The pairing is Zenitsu/Kaigaku, Zenitsu x Kaigaku, with no secondary pairings.

3. Canon Kaigaku is a scumbag, so this time Zenitsu will probably be making trouble by clinging to his senior brother before he turns into one. Or, in other words, tormenting his own senior brother? Under the brotherly devotion Zenitsu barges in with after being reborn, Kaigaku will turn into a good kid who's a little fierce.

4. The story starts before the Stone Hashira's demon-smashing incident, so Kaigaku hasn't done too many bad things yet.

5. Reborn Zenitsu is using his original body, so he won't affect the Zenitsu in the normal timeline. There will be a point later where two Zenitsus show up!

6. The author is very fragile, very (!) easily affected by readers' comments! Please don't explain what a scumbag senior brother is under the author's story! Thank you, thank you!

7. A lot of characters will get to dodge the death flags! The author loves happy endings where everyone gets together.

A recommendation for another Zenitsu/Kaigaku story: My Senior Brother Hasn't Been Defeated by His Golden Finger Today Either!

As an old fossil burdened with the memories of a past life, reborn in the Taisho era, when computers and cell phones didn't even exist, Kaigaku really couldn't stand his golden finger.

Its childish introductions, its flippant attitude toward the world, and its habit of forcibly taking over other people's brains all made it hard for Kaigaku to like.

But the world he had been reborn into was crawling with curses, and when he was on the verge of death, the System that answered Kaigaku's call became his only chance to survive.

And so began a long struggle against a golden finger with a twisted sense of humor.

[Bam bam~ Welcome to the Mini-Game System~ Life is one grand game! Find the trick, solve the puzzles, and clear the levels~]

[Life Simulator]

[Ding~ Drawing your talent now]

[Draw complete~ Your talent is: Potential (When household wealth is below 0, cursed energy +1)]

Kaigaku: ??? Is this making fun of how poor I am??

Before he could downvote this ridiculous talent, it had already activated automatically.

A young man with round sunglasses, seeing Kaigaku for the first time, opened his eyes wide in surprise. "Wow, you have an incredible amount of cursed energy..."

Kaigaku, who was poor enough to eat dirt, gave him a poverty-stricken eye roll.

But when Kaigaku accidentally discovered how to exploit a bug, things quickly got out of hand.

One day, after the nth time that a girl with a cursed restriction had borrowed a cursed tool from an upperclassman a year ahead of her, only for him to put on a show of giving it to her, she stared with a head full of question marks.

"Bastard! Is it fun to keep giving away stuff you borrowed from other people??"

Kaigaku said nothing. He just kept exploiting the bug.

Household wealth -1 -1 -1, cursed energy +1 +1 +1

His immense cursed energy fed the yellow-haired curse attached to him until it grew fat and strong. Then one day, the shameless scumbag of an adult dragged Kaigaku in front of another scumbag.

"Come on, come on, Kaigaku! Hurry up and use that move on him!!"

Kaigaku's temple throbbed. He took a deep breath and raised his hand, while the curse on his body struck a pose to match.

"How rude. We're pure love!"

[Dreamy Cottage]

[Beat match-three levels, upgrade your facilities, and get everything you want!!]

"Great!"

Kaigaku cut down the third Fly Head. As he watched the cutscene show three Fly Heads being mashed together and tossed into a pot, the lid opened and a steaming, delicious-looking loaf of bread appeared in his palm. Suddenly, he had no desire to eat at all.

A young man with smiling eyes cheerfully held out a blackish cursed spirit orb. "Help me out, Kaigaku-sensei!"

"I want to dye this thing green... Wait, no! Spicy!"

[Miracle Dress-Up]

[Become a styling master! Fight in the clothes you love! The higher your rating, the bigger your bonus~]

Kaigaku expressionlessly put back the glittering frilly dress and cute matching hair accessories he'd gotten from a ten-pull, picked up the white stockings and garter that had fallen on the ground, and began questioning his life again.

Wearing this to fight curses? He'd rather go and s...

"Woohoo~ Magical girl transformation~ Suguru, your flower fairy outfit can't beat mine~"

"You don't understand, Satoru. Stats are what matter most. My flower fairy outfit has a full five percent more critical-hit bonus than yours. So the flower fairy wins."

The scumbag adults were having a blast.

Was becoming a strong person really contingent on becoming a shameless scumbag like these two...?

Watching the two strongest people dress themselves up as Christmas trees without a care in the world, Kaigaku questioned this world for the nth time.

The golden finger was ridiculous but genuinely useful, and Kaigaku's strength began to skyrocket. In return, his reputation plummeted off a cliff.

"Sure, he threatened to kidnap me the moment we met, fed me and Tsumiki meals made out of curses, put everyone in a dress before every battle, and has weird techniques... But Kaigaku-nii is a benefactor to both me and Tsumiki." The spiky-haired, sour-faced junior said.

"A pitiful scumbag who got led astray from studying under two scumbag teachers. He's always borrowing other people's cursed tools and passing them around. He's reliable apart from that." The cursed-tool expert said.

"Salmon! Salmon!" The descendant of the Cursed Speech clan held up a green sign with a big check mark on it. (A magical senpai who can produce throat medicine at any time! Translated by Panda.)

"Though Gojo-sensei is always directing him to say weird things in front of me and Geto-sensei... he's very reassuring." The fourth special-grade sorcerer said.

"He can be a little too serious and really admires the strong... but he's a good kid." The folks at Tokyo Jujutsu High said.

"A variable. A variable in the world. A child expected to grow up." One of the two strongest said.

"He is the new hope of the jujutsu world, a junior I can entrust things to, and my most prideful student." The teacher with the man bun smiled with his eyes.

Kaigaku had no idea why he hadn't forgotten his past-life memories when he was reborn, but he'd decided to treat everything about demons and demon slayers from his previous life as a dream and wholeheartedly live his new life... until one day, to his horror, he discovered that the companion curse he'd always called by the name of the junior brother he hated in his past life... was actually that very junior brother, reborn as well??

Kaigaku even dreamed about it, wondering what he could possibly have done to his junior brother in his past life to make him cling to him even as a curse after being reborn.

But his junior brother acted as if Kaigaku had betrayed him, rambling on about a promise Kaigaku had no memory of making.

"What are you talking about, Senior Brother?" Zenitsu opened his eyes wide and said innocently, "You promised me, remember? If I found you, we'd never be apart for the rest of our lives."

He smiled, eyes curving, wrapped his arms around Kaigaku's neck, and pressed his cheek against the side of Kaigaku's neck.

"We promised forever. If we're apart for even one minute, one second, then it isn't forever."

"Senior Brother, this is a curse we made on each other."

Content warning: The protagonist is Kaigaku, the senior brother of Demon Slayer's Zenitsu. Readers who strongly dislike Kaigaku may not want to click in.

Pairing: Zenitsu/Kaigaku. Crossover with JJK, Mob Psycho 100, and Demon Slayer, with Gojo/Geto and Mob/Reigen appearances.

Little Kaigaku mistakenly reborn into the JJK world, and little Zenitsu, who dreams every night in the Demon Slayer Academy world that he has become the curse attached to his senior brother.

They will cross between worlds in the middle and later parts of the story, with the goal of finding a world where little Kaigaku can be happy. In the end, little Kaigaku will be able to travel between several worlds and get everything he wants.

Premise: Everyone deserves to be saved