#kagaya and amane already have their interactions

[romaritimeharbor]

300 to 10k words is so devastating i am literally so close

[echantedtoon]

Been tossing around ideas for this with @lavenderdrxp and I find this idea absolutely hilarious. Takes place in Kimetsu Gauken.

*You are Muzan's fiance but not by choice. It was an arrangement made by your families when you both were younger as part of a business deal.

*Despite being his 'fiance', Muzan doesn't even acknowledge your presence unless he absolutely HAS to. In fact he even legitimately forgets you even exist most of the time too busy with his plans to take over Japan. He's a pretty sorry excuse for a fiance. The only reason you haven't just called it quits yet is out of respect for your family but you're very close to not caring anymore and calling the entire thing off. It's not like he'd care.

*Despite this one day he actually does acknowledge you!... Because he wants to use you to infiltrate Kimetsu Academy to spy on his Cousin Kagaya.

*Up to this point Kagaya and Muzan hate one another only acting distantly cordial at family gatherings if even that. Despite that Kagaya has never met You. He knows his cousin was engaged but he's never met Y/n (mostly Muzan's fault for refusing to bring you anywhere EVER), so You would be the perfect spy. (Brilliant thinking am I right?)

*You reluctantly agree only on the basis that he shuts up about this entire thing he won't stop bugging you about.

*You set up a meeting with Kagaya via Muzan giving you his number and intergrade yourself into the Academy's staff as his and Amane's new secretary. Giving you access to many of the Academy's...grading papers. And student profiles and... There's nothing here that screams 'government Intel's or anything Muzan would want. It's just a normal every day school.

*He INSISTS that you keep looking around much to your annoyance.

*Kagaya and Amane know the entire time btw. Muzan isnt as clever as he thinks he's being. They knew from the moment Kagaya interviewed you for the job, but he found his cousins attempts to sabotage him quite amusing and let you stay.

*Slowly things start turning. You start to really enjoy your job at the Academy. You've already made friends with a few teachers like Kyojuro, and Kanae.

*Students start to like coming to the office more because of how bubbly and friendly the new secretary is. The teachers start to talk to you more often and invite you to staff parties and outside work events.

*Was working outside your old job really this fun? You couldn't remember the last time you actually felt appreciated or just had someone WANT to talk to you.

*As part of your 'mission' you were supposed to get as close to the Ubuyashikis as possible to learn about all their little secrets. Again they already know but they're curious about what you'll do so they allow you to (not so discreetly) come around them and speak to them often.

*Kagaya thinks it's amusing watching you shyly peek into the doorway to his office with papers clutched into your hands and bashfully asking if you could come in. The way you so innocently look unsure of something or squeak out a question. It's adorable seeing your attempts.

Amane finds your sweet and bubbly personality is perfect for the job! Especially when she sees how much you love interacting with the students and always friendly towards her own children. When you shyly ask her for help with scheduling or ask where a certain file is, always puts a smile on her face.

How could someone like Muzan be engaged to someone so sweet?

*It's Amane that finally brings up the topic. She accidentally walks in to you crying as Muzan is yelling at you over the phone calling you names before hanging up and leaving you a sobbing mess she quickly comforts. Assuring you that it'd be alright and the three of you should have a long talk.

*You're surprised that they knew, but too tired and stressed out to care allowing the couple to hug and comfort you.

*Muzan shouldn't really be surprised when one day he attempts to contact you and finds himself blocked from all your socials. He's been in contact with you this entire time so what the hell is going on?! He gets Kokushibo and a few other employees to text/call you to tell you to quickly get in contact with him. But they all either get completely ignored or blocked too. He's frustrated more and more everyday that you don't contact him.

*Until one day you unblock him to text him ONE word before reblocking his number- "Goodbye."

*Muzan is confused, offended, and mostly pissed! Goodbye?! What the hell does she mean by goodbye?! Doesn't she know who she's dealing with?!

*Not too long after he gets a text message and photo from Kagaya and Amane. Annoyed he opens the message from his cousin and his wife only for a glass shattering noise to go off in his head, and his jaw drop to the floor-

*It's a photo of You in the middle looking beautiful and happy with Amane and Kagaya on either side of you showing off a beautiful New diamond ring on your ring finger-

Amane: "Thank you for introducing us to Y/n. She's such a a lovely woman. You'll be receiving your wedding invitation soon."

Kagaya: "No bitches?"

Kagaya: "You really need to reconsider your plans better if you want to stop looking like a fool."

Kagaya: "Btw have you met our fiance? lol"

*Muzan has to get a new phone after chucking his in rage. Poor Kokushibo literally has to hold him from behind and keep him from storming into the academy and making a fool of himself.

*He doesn't attend but as a polite gesture (a.k.a Kagaya rubbing it into Muzan's face), he is sent a final message in the form of y'all's wedding invite.

Tagging: @lavenderdrxp

[shiratamahatsumiyo]

Gun Park with Amane Ubuyashiki reader, ft. Daniel Park (Part 1)

There are two ways that Gun can meet you. Either as a Himorogi or an Ubuyashiki.

• If you are a Himorogi, then you are still a student of religious studies in Shintoism. Your grades are so high and perfect that you became the class president of the Religious Studies Department (founded by yours truly). You are also very intelligent that you can rival student prodigies in the Science and Mathematics Department.

• Your beauty is also an aspect of what you are known for in Jaewon High , the large amount of admirers that worship your graceful and elegant aura is astonishing to the point where students thought you should've been in the Beauty and Cosmetics Department. A lot of women are jealous of you because of the same reason and some even threatened you, but you remained calm and expressionless. That lifeless look in your eyes intimidated many people but also made them feel drawn to your mysterious personality.

• You befriended Daniel after hearing him from Kagaya's crow. It told news about it witnessing one of the Ubuyashiki rivals, Charles Choi's daughter and bodyguard stepping into the school grounds. You immediately got up from your library study and head straight to the school festival.

• You made sure to keep distance from the pretty woman and black-eyed man to spy on them. Not even one hour and Gun is already starting a fight... Well, it's actually not him that started the fight, it's that Daniel Park boy who insisted on talking to the girl but the bodyguard prevented him from doing so.

• Luckily, Vasco interrupted before Gun can pulverize Daniel some more. The fight was broken off by Crystal and the two outsiders left the campus. You stepped out of the shadows and joined the injured two, offering them first aid. Vasco insisted that he doesn't need your help but was influenced by your persistent demeanor and let you treat his nose. You politely bowed to introduce yourself to the boys and looked at Daniel for permission to treat his bruise. The flustered handsome man nodded his head in a yes gesture. After that encounter, the rest of you enjoyed the music festival.

• Time flies by and your relationship with your peers improved. You managed to befriend Zoe, Mira, Zack, Vasco, Jace, and even Jay. But at the same time, you were emotionally distant and interacted with everyone only at arm's length. Your quiet behavior and creepy eyes unnerved them a bit.

• Daniel is starting to question you why you became more involved in his life and you answered,

Amane! Reader: "I saw the way you fought that man... If Gun sees potential in you to be his successor, then we'll all be doomed."

Daniel: "...C-Come again...?"

• You explained to Daniel that if Gun were to recruit him, he will train Daniel the ways of a merciless and ruthless fighter and if he succeeds his training through further recruitment from the higher ups, he will be tasked by Charles Choi to destroy the Ubuyashiki family and the Himorogi family as well as the connections that are tied to the two clans.

• Your family may be representatives of several Shinto shrines but even they have some connections with the Ubuyashiki clan, who own a corporation of highly trained fighters targeting gangs and other illegal unions. The corporation is large enough to reach from Japan to South Korea and their most powerful fighters guard and control districts undercover. These top fighters are called Hashiras and each one of them have a reason for joining the corporation as well as a reason to fight. Their fighters are known for having constant conflict with an organization called The Twelve Kizuki.

• Unfortunately, Gun Park, one of the top fighters from one of the corporation's rivals, is eliminating the fighters one by one, causing a major problem for the corporation. You plan on recruiting Daniel and train him to defeat Gun, even telling Daniel that the corporation offers rewards and incentives if he joins you but it still his choice to make whether he wants to work with you or not.

• Weeks passed, due to the increasing homework and performance tasks dumped handed by the teachers, your friends are too worried about the deadline and forgot about that incident. You, on the other hand, counted each day after that. Who knows when Choi will strike?

• One day, you decided to ask Daniel for his final answer and walked home with him. However the moment is ruined when an expensive looking sports car suddenly parked in front of you. The driver of the car came out and look who it is... Gun Park himself.

• Daniel became alert but you remained calm. You can tell by Daniel's stance that he's ready to throw hands. Gun ignored the sudden defensiveness and then asked the boy if he's reconsidered his offer. Outwardly, you are unfazed by the interaction but internally, you are surprised at the hint that Daniel may or may not have told you about Gun's offer. Gun walked closer to you two and stared at Daniel for any indication of the boy changing his mind but you stepped in front of Daniel.

Amane! Reader: "Excuse me for interrupting, but we have somewhere urgent we need to go."

• He made eye contact with you and leaned closer, his height intimidated many but you stood your ground. An awkward silence fills the tense atmosphere as you and the tall man engage in a silent glaring contest. It felt like the abyss is glaring back at the void.

Gun: "Hey. Move."

Amane! Reader: "... I'm sorry but I won't."

• Well, this looks like it'll be difficult to shake him off. He's the first to cut the glaring when he turns his piercing gaze at Daniel. He walked past you and placed his hand on Daniel's shoulder, he brings his mouth close to his ear and whispered...

Gun: "Listen here... if you want to train your body to its fullest potential and master techniques to an extent, then accept my offer, yeah?"

Daniel: "........."

• Gun drew his hand back to his pocket and smirked. Daniel didn't respond and just looked at you with guilt in his eyes.

• Don't tell me... He's actually thinking of...?

• A blur flashed by your eyes as Gun almost kicked you in the side of your head but his leg stopped mid-air. The black-eyed man is actually impressed that you didn't flinch. Daniel was about to intervene your little confrontation but stopped after you held your hand up as if to signal a stop sign to him.

• You look at Gun, no fear evident in your eyes. It's almost as if you're mocking him...

Amane! Reader: "Is that all?"

Gun: "....Yes."

• The man didn't say anything further and went back to his car but not without reminding Daniel of the offer's deadline and then drove off.

• You and Daniel continued to walk home. He wanted to apologize but you gave him a final warning to never accept Gun's offer and left.

• You grew more worried about Daniel as he makes his way to one of the top fighters in school, making enemies left and right. But he also gained allies. Like you, for example, you keep reporting to Ubuyashiki as to protect Daniel from the eyes of other organizations. However, Gun was getting impatient.

• Gun was called in by Charles Choi for a new task. He gave him an assignment that requires him to bribe someone and if they decline, he must kill them. An typical assignment that bores him to the point where he thinks that Goo was more suited for the job. But all it took was one glance at your file and he became interested. Charles noted Gun's eyes filled with recognition upon scanning through your profile and assumed he was at least familiar with you.

• He kept the file and walked out of the office, he'll read more of it in his car. No wonder you're so protective of Daniel Park. You had an ulterior motive for keeping that guy away from him.

• The bell rings and you go outside of the entrance gate to wait for Daniel, in hopes of hearing his decision. Your wait was interrupted by car rolling its window down which revealed Gun Park as the driver. Your body froze. This is bad. Daniel hasn't exited his classroom. And you're certain that this man is MUCH more powerful than you in terms of strength.

• The man got out of his car and begin slowly approach you. Every painfully slow step he takes towards you feels like you're facing a demon... He stops and just stares at you. Despite the difference between your intimidation tactics, you're not backing down. Another glare-down with hidden conflict was engaged. Both of you neither talked, just glared. The only sound there is are the loudly chatting students exiting from the school's entrance.

• After a long while, Daniel still hasn't arrived, and the loudness of the students become muffled until they've gone their way home. The silence was no longer on your side anymore, it's making you uncomfortable enough to speak first...

Amane! Reader: "... Pardon me, may I ask for what motive do you have to come all the way here?"

Gun: "...I'm not gonna waste both of our time... I have a proposition for you."

Amane! Reader: "... A proposition?"

Gun: "Yeah... It's simple. If you leave Daniel Park, you live. If you won't, you die. Deal?"

Amane! Reader: "And what makes you think I'll accept this one-sided offer?"

Gun: "Does the name Charles Choi sound familiar?"

Amane! Reader: "..............."

Gun: "He wants you to work for him. For you to leave the Ubuyashiki corp. You get paid and other benefits."

Amane! Reader: "......How do you..."

Gun: "Read your profile. From the looks of it, you're more than just the Ubuyashiki head's right hand. You're also the head of the Himorogi family's Shinto shrines. I commend you... Not everyone is talented at hiding their identity for so long... Not even from that brat... So, what do you say?"

Amane! Reader: "I am not easily swayed by mere threats and bribes. If you don't have anything else to say, then have a good evening."

• You tried to walk away to get Daniel but a hand grabbed your shoulder and pinned you to the wall. The impact of your back to the cement was strong enough to put cracks on the wall. Gun's gripping hand digs into your skin, you're pretty sure that your bone cracked as well. It was so painful that you wanted to scream help but you know that he'll drag you and kill you. You have no choice but to endure the pain. Just for a bit.

• Gun's piercing jet black eyes glared down at you filled with bloodlust, urging you to give up and surrender. But you still didn't squirm, no trace of pain was evident on your face, not even a wince. You glared back at him...

Gun: "........This is your last warning....."

Amane! Reader: "..........I....Humbly...... Decline....."

• ... Until he let go. He draws his hand back as if he merely squashed a bug. There's hint of irritation on his face. He doesn't understand how a weakling with no fighter's will or experience in fighting stand their ground against him. But for some reason he felt... intimidated?

• For now, he'll let you go.

Amane! Reader: "....... Daniel is a good person..... He'll fight if he needs to..."

Gun: ".... We'll see about that."

"AMANE! READER!!"

• Ah, speaking of Daniel, here he comes now. He ran toward you and stood in front of you, shielding you away from Gun. Daniel held his arms up and shouted at Gun.

Daniel: "What do you want from them?! If you want to fight, then fight me! Don't involve them!"

Gun: "No, they are very much involved."

Amane! Reader: "Daniel, I'm fine. Please don't fight."

Daniel: "W-what? But he..."

Amane! Reader: "I'm sure Gun was just in the middle of leaving.

Gun: "......Yeah. I'm not in the mood right now... I'm leaving."

Daniel: "H-huh...?"

• Well that was unexpected... Usually Gun is constantly in fight mode. He's leaving without a fight from Daniel? The man practically can't survive a day without a fight. But today he withdraws. Daniel put his arms down and just looked dumbfounded. He has lots of questions for you.

• Gun opened the door to his car, he was about to climb in but he looked at you...

Gun: "Hey... Himorogi."

Amane! Reader: "...?"

Gun: "Whatever the hell's wrong with you, I like your boldness. That deal is offered once so expect to be hunted down."

Amane! Reader: "... I'm aware."

• With that, he drove off to report to Charles. He definitely knows that Goo will tease him about his withdrawal and "How the mighty Shiro Oni was scared off by a weakling." He'll have to punch his jaw harder later.

• ..........................

• He couldn't get his mind off of you... Those lifeless, void eyes of yours reminded him of his own, except that they have a somewhat tranquil yet secretive charm. How does the expression go? The eyes are the windows to the soul? Is that how they say it?

• Hmm... It looks like Daniel's answer is going to have to wait. He needs to know more about you...

• As he learned more about you, he realized that you were far more intelligent and mentally stronger than he thought. According to whatever information Kouji gathered, you faced off enemies of the Corp. without even lifting a finger.

• When facing an opponent, you would place hidden traps ahead of time before observing and memorizing the loopholes of the opponent's fighting style. And since you have an expressionless face and laser-focused eye contact, it makes harder for the opponent to predict your next move.

• Your physical strength is low but your mental and academical strength exceeded greatly to the point where you negotiated with leaders from gangs without much conflict. These information intrigued Gun to the point where he thought observing you himself in the shadows.

• He learned that your abilities earned you respect from both the school and the corp. Although some of the fighters there don't cooperate well with each other, you are patient and maintained a calm demeanor towards all of them, while their differing personalities unfazed you. You trained yourself with advanced leadership skills that are equivalent to the Master's in order to give proper commands.

• From all the Hashira fighters Gun has defeated, all of them remained loyal and never revealed who you or the Master are. Even if they won and returned to you with broken bones and regretted ever taking damage, you and the Master would forgive them for their mistakes, brush it off and call it progress.

• You managed to lead both the corp, your family's Shinto shrines, school assignments, and aiding your ill Master, all at the same time. Gun has never seen such loyalty before. To think all of this weight of responsibilities on your shoulders from a young age to 17. You are truly worthy of the Ubuyashiki head's right hand title.

• You really are interesting... Gun makes sure that when you two cross paths again, he'll fight you to see for himself.

[huntinglove]

Here's some stuff I think the Hashira and the Upper Moon's are into, because I'm a whore :3

(Note, I don't selfship with all of these characters, I just wanna ramble about this because it helps me characterize them better when I write)

Minors please don't interact

Muichiro: Definitely enjoys going soft and easy at first then getting insanely rough when questioned about it, he knows he can absolutely ruin someone, but he likes taking his time with it

Giyuu: Loves having sex when he knows there's people in the next room over, both because he finds it fun to watch his partner squirm without making a sound and because he's shy and doesn't like being too loud

Mitsuri: Will come up with all sorts of roleplays and fantasies, sex would never become a repetitive routine with her. She also enjoys doing these scenarios out of nowhere, so her partner will have a more genuine and spontaneous reaction

Obanai: Crazy about bondage, seeing his partner tied up in any way makes him all hot and bothered. He's a huge tease about it too, he'll edge his partner until they're almost crying and begging for him to let them cum already

Rengoku: The king of praise and body worship, his partner will have their ego and confidence through the roof after having sex with him. He's very talkative and loud all throughout and shyness has no place around him. Hell praise his partner and make them repeat his words back to him while pounding away at them

Gyomei: Size kink all the way, loves fingering his partner because he can easily spread them open for him using only his hands. His senses of smell and hearing are probably heightened because of his blindness, so any whimper is immediately detected by him, as well as any perfumes, lotions and lube his partner chooses to use

Uzui: Group sex is definitely his favorite, watching his wives play with his partner to get them ready for him drives him insane, especially if he's getting his cock worshiped at the same time. He also adores fancy and flashy outfits, lingerie, jewelry and kink gear makes him want to fuck his partner in front of a mirror, so both of them can see how beautiful they look for him

Shinobu: Possessive as hell and loves to remind her partner that they belong to her and only her. She'll speak softly but will bite, scratch and leave hickeys all over her partner's skin, especially in visible spots so others can know that her partner is already owned by someone

Sanemi: Violent sex, he'll take out all his frustrations on his partner when they fuck, a hand wrapped tightly around their neck while he splits them open with his cock. He's messy as hell and will leave his partner covered in his saliva, cum and their own blood once he's done with them

(Bonus) Kagaya: Huge softie and really enjoys taking his time, not in a teasing way but to help make his partner feel more relaxed when they're with him. Slow sex is greatly preferred for him and if his partner is okay with it, he'll ask Amane to join them and just have a very calm threesome, usually just kissing both of their bodies and tasting them for as long as he can

Kokushibo: Greatly enjoys marking, as well as knifeplay, he'll always make sure to carve his name somewhere on his partner's body and lick up the blood afterwards. Also loves to fill his partner up with his cum and make them describe the feeling of being full of his seed

Douma: Loves religious roleplay and being worshiped by his partner. He'll have them call him "My perfect God" and do as many degrading things as he feels like telling them to. Would love to fuck his partner in front of his followers to show how benevolent and adoring he is to those who listen to his words

Akaza: Words go completely against his actions, he'll praise and coo at his partner for being able to take him so we'll, while shoving them down at his cock and grinding their insides as roughly as he can. Most of the time he doesn't even notice that he's being rough, he gets very caught up in the moment and just lets his instincts take over his body

Hantengu: Greatly enjoys having sex with his partner and his clones at the same time, so he can feel five times as much pleasure. Needs praise, it fuels him more than anything, especially while he's grabbing and groping his partner's body while his clones pound away at their holes

Gyokko: Twin cocks and sentient vases, he enjoys being stroked and treated like a superior, will try to act smug but will end up stumbling over his words more and more depending on how excited he gets. Loves to have his partner immobilized one way or another, like a living piece of art for him to play with and admire

Gyutaro: Any time, any place, for any reason. He gets horny as soon as his emotions get the best of him so him and his partner will have sex whenever he's upset, angry, happy or just bored. Doesn't know how to handle praise so he'll just shove his tongue in his partner's mouth as soon as they start to make him flustered. If he really trusts someone he'll offer to have a threesome with Daki, when that happens he expects his partner to worship her and take him like a good fuck toy

Daki: Extremely sensual with the way she presents herself and it's impossible to miss her hints at wanting to have sex with someone. Loves being worshiped and worshiping her partner as well, especially if she gets to make them praise her while she touches them. Can be rough and degrading towards her partner if she feels like it, loves to slap their face red for being such a pervert and needing her this much

(Bonus) Muzan: Absolutely brutal with how he has sex, no matter what. He's possessive, dominant and inhumanly strong, if he goes easy on his partner they'll at least end up with a shattered femur. Will have them bound and at his complete mercy, loves to watch his partner come undone, getting covered in blood, tears and cum while begging for his mercy. His partner will be treated like a living sex doll and be repeatedly used until he's thoroughly satisfied, which can take anywhere from hours to whole days

[demonslayedher]

An Attempted Timeline: Kochou Shinobu

Very open to feedback, because canon is as spread out as Muzan after his first date with Sun Breathing. Instead of tracking the year or distance from current timeline, we shall track this by Shinobu’s age (roughly, in most spots).  Despite being centered around Shinobu’s life events, I’m also diving into Aoi’s life, the other Pillars’ timelines of life events too, and doing some conjecture about Shinobu’s deceased Tsuguko.  Should be obvious, but spoilers ahead. 

Childhood: Raised by kind parents who possessed medical knowledge. Sometime around elementary school age (at the oldest, I’d put her at 11, but probably younger), parents are killed by a demon, house is demolished, and she and Kanae are rescued by Himejima (who was maybe around 20 or younger at the time), who hands them off to the Kakushi. After the funeral for their parents, she and Kanae seek out Himejima for training, and after a little time with them he sends them to separate cultivators (according to the light novel chapter “One Winged Butterfly.”) Training under cultivators usually takes about a year. She and Kanae perhaps passed the Final Selection when Shinobu was around 12-ish, give or take.  (For setting and comparison’s sake, Kagaya and Amane have long since already been married and Kiriya is already born.) Whether Kanae becomes a Pillar first or they establish the hospital at the Butterfly Mansion first is unclear, but these events happen relatively quickly. I suspect they might have had access to a lot of savings from their parents. Furthermore, this makes Kanae one of the many Pillars in the recent generation who blows that “it usually takes five years to become a Pillar” Taisho Secret away. (As an aside, maybe the reason the Corp as a whole seems to be full of weaklings is because the current Pillars have sucked up all the amazingness, but I digress.)

The Butterfly Mansion’s hospital was established long before Sanemi became a Pillar (according to the light novel chapter “Signpost of the Wind”). Sometime after Kanae becomes a Pillar, Sanemi becomes a Pillar. Giyuu was a Pillar before Sanemi was; the three of them were the same age. My guess is that Shinobu was around 13 when Kanae became a Pillar, putting Kanae and Sanemi around ages 15ish~17 when they would have had chances to interact. For comparison, Giyuu and Sabito were 13 at the time of the Final Selection, so Giyuu would had already been in the Corp longer than Kanae and Shinobu.

The following events either happened very quickly or unfolded over the course of a couple years:

Aoi (likely the the same age as Kanao) comes into their care (she preceded Kanao since she was there for Kanao’s naming, according to Taisho Secrets and second fanbook)*

Kanao (two years younger than Shinobu but much smaller, and given how petite Shinobu is, I can only assume this is because of how malnourished Kanao was) is adopted as their little sister on some May 19 (the anime seems to put the event in winter, but I assume it was already in production before the first fanbook was published with that detail)

Kanao has ample opportunity to observe Kanae’s Flower Breathing and learn by watching

Kiyo, Sumi, and Naho come into the fold (separately or all at once, though not as relatives)

Kanae is killed by Douma (Shinobu is age 14, one of the only pieces of this timeline we can be certain of). As she wished in her dying moments for Shinobu to live a normal life, she may or may not have had Shinobu as her Tsuguko, or had any Tsuguko at all.

Shinobu, age 14, becomes the head of the Butterfly Mansion household, where she already has five adoptive/pseudo younger sisters. At this point she takes on a cheerful personality, as well as probably set her heart on becoming a Pillar as soon as possible and becoming strong enough to defeat the demon that killed Kanae.

*Aoi’s circumstances are important (and curious) because the second fanbook tells us both that she practiced Water Breathing and that she passed the same Final Selection as Muichiro. Since Muichiro became a Pillar two months after taking up the sword, that means he went almost straight from sword to Final Selection to Pillar. We don’t know how much recovery time he needed after losing Yuichiro at age 11, because he wasn’t among the Pillars in the Rengoku Gaiden, so he perhaps only started practicing the sword closer to late 12 or age 13 (putting Aoi around 14, 15-ish when she passed the Final Selection, and presumably quit the sword right after that).  It’s interesting to note what a different relationship Aoi has with Shinobu than Kanao does, especially since Aoi was there first but Kanao was adopted as a sister in a more all-encompassing sense. I suspect (and am putting this in italics for conjecture): Due to whatever circumstances with her Water Breath cultivator (possibly difficulty in housing a lone girl among a bunch of male students), Aoi needed to live elsewhere during her training. The Butterfly Mansion was a good spot, so Kanae and Shinobu agreed, like sponsoring a junior, and in exchange Aoi helped out around the house and hospital. Aoi kept her own last name, as she had her own family to avenge. When Kanao came in, it was purely out of wanting to help an orphan who wound up staying with them instead of being adopted out, which is why she was given a family identity and an opportunity to take the Kochou name if she wanted to (or even Aoi’s family name). They were probably treated differently because of the nature of how they came in and an assumption that Aoi would leave as soon as she entered the Corp. As Kiyo, Naho, and Sumi came in, it was a weird middle ground of whether they were just looked after until something better for them came along or if they were adopted as sisters as fully as Kanao was. Ultimately, they still retained a lot of their identities from before they were orphaned, and it was more of a pseudo-sisterhood, which Aoi had sort of fallen into as well. But, once Aoi entered the Corp and then quit the sword, she probably didn’t feel she could turn to her cultivator for any help, so at that point Shinobu took more full responsibility for her as a permanent household member.

Moving back on to Shinobu’s timeline, if I’m remembering the Giyuu Gaiden correctly (it’s been a while since I read it so I don’t recall exactly), that story took place shortly after Giyuu sent Tanjiro and Nezuko to Urokodaki, and it was also shortly after Shinobu became a Pillar. Since Tanjiro took two years to train after that, that would put her at age 16. Since Kanao joined the Corp in the same batch as Tanjiro, that means Shinobu would have had about two years between becoming a Pillar and taking Kanao as her official Tsuguko (I stress ‘official’ because it comes with distinction Tengen respects, it’s not casual “sure, I’ll look after you” thing). In that time, she had (at least) three other previous Tsuguko, all girls given butterfly hairpins, and who were all killed by demons in that two year period. 

Conjecture about Shinobu and these Tsuguko: 

Knowing how likely she is to be killed before she has an opportunity to avenge Kanae, Shinobu was likely in a hurry to train a Tsuguko and started trying to pass her knowledge on right away. It’s possible they were even closer in age to her than Kanao, maybe even older, and quite possibly physically stronger. It’s possible they were trained under Flower Breathing cultivators and still used that Breath, which would have given Kanao opportunities to learn by watching.  That said, Shinobu doesn’t mention or think back to her Tsuguko often, and they never appear in Kanao’s flashbacks, though their deaths are some of the little pieces that strengthen her resolve to slay demons (she seems to care more about how her pseudo-sisters’ families were killed by them). My guess is that Shinobu made a clear divide between family and work, so as to protect the little girls from getting attached to more people who were likely to be taken away from them. Likely, her Tsuguko and the Butterfly Mansion girls resided in separate spaces and had very little interaction, and their Pillar/Tsuguko relationship was kept very formal so they could all focus on their demon slaying goals (albeit they were probably fond of each other anyway, signified by the butterfly hairpins). 

In that two year period, the following events occur in roughly this order: 

Rengoku become a Pillar (around age 18 or 19, and since he was raised practicing Flame Breathing he probably finished the Final Selection around age 12 or 13, so it clearly took him a more normal period of time to become a Pillar. But, despite being naturally gifted with strength his mother recognized, this drives home how hard he needed to work to overcome a perceived lack of “talent.”)

Iguro becomes a Pillar (around age 19 or 20, so he likely had worked at it a long time)

Aoi passes the Final Selection and quits the sword (thereby leaving Shinobu able to leave most of the hospital and household work to her since she’s no longer training), Muichirio becomes a Pillar (around age 12 or 13, genius-level speed at attaining Pillarhood)

Mitsuri becomes a Pillar (around age 18 or 19--a friend, yay! Also someone who became a Pillar way faster than normal.)

On these note, please also me to jump backwards a few years to when Kanae was still alive. Uzui had to have been a Pillar by at least age 18, but given the state of Ubuyashiki’s illness, probably a lot earlier than that, and he probably didn’t take very long to become a Pillar after entering the Corp. Since Giyuu was already a Pillar in Sanemi’s flashback, then he attained Pillarhood by, at the very oldest, age 17, so it took him four years or less. Interesting that in all these four or more years he’s been convinced the position is vacant, there’s no one else who performs Pillar-worthy achievement in the Corp’s most widely used Breath style. That really drives home the difference between the Pillars and the average cannon fodder. (Also worth noting, the Kamaboko Squad’s progression seems to fall somewhere in the middle; right to the very end the Taisho Secrets state how Tanjiro was still far from mastering Hinokami Kagura.)

At late 17 or age 18, two events occur: 

Shinobu begins filling her body with poison for the sake of exacting revenge, knowing she will likely be eaten (she began about a year before the Pillar Training arc)

Kanao sneaks out to the Final Selection of her own will and with self-studied Flower Breathing, officially becomes a member of the Corp. Shinobu worries Kanao was just doing this because it’s what everyone around her does, as Kanao cannot express that she’s built her own hatred for demons. 

Shinobu makes Kanao her Tsuguko almost right away, making the following changes (conjecture in italics):

Teaching her proper Breathing and sword technique (and the little girls witness her quick progress with blowing up gourds)

Instructing her very simply just to focus on cutting on demons’ heads so that she doesn’t get caught up in indecision on the battlefield

Censuring Kanao a bit for her choice to go against her sisters’ wishes and take up the sword, for now she risks death and giving the other pseudo-sisters yet another person to grieve. Given the risky nature of their work, Shinobu feels forced to treat her the same strict way she treated her Tsuguko instead of treat her as a sister. Kanao accepts this and goes from treating Shinobu as her sister to treating her as her master (calling her “Shihan” instead of “Shinobu-neesan”).

Over the course of the events of canon, Tanjiro and company spend a very large portion of their time in recovery at the Butterfly Mansion (even if a large portion of that time is spent unconscious), they might as well be pseudo-adoptive little brothers. But, I suspect Shinobu bonds more readily with girls. Also in that time, Kanao speeds up the ranks (she attains Hinoto rank, the 7th of 10 ranks, while Tanjiro & co attain the one above that, Hinoe). Furthermore, thanks to Tanjiro’s influence, Kanao also makes leap and bounds in being able to express herself, like something finally broke through.  This at last leaves Shinobu somewhat relieved, after maybe five years or so since she first adopted Kanao. By that time she is getting anxious about the impending final battles (and her death, which she has deemed inevitable but purposeful), and she tells Kanao the plan. And then Oyakata-sama is like, “heeeey, so I heard you want to be friends with demons, I got you one, her name is Tamayo.” (It’s possible he already told her he was planning to get Tamayo’s help and wanted her cooperation, but he didn’t actually approach Tamayo about it until after Pillar Training started (though by Kimetsu logic, it’s highly possible that the crow talking to Tamayo took place much earlier than when it was presented). I gotta wonder how quickly they worked to combine their research and if the other girls in the mansion had any idea who Tamayo and Yushiro were.

And then, at age 18 (or likely 19 given the progression of the series and very lengthy recovery periods, heck maybe even 20), Douma. Shinobu dies, Kanao switches back to calling her Shinobu-neesan instead of Shihan, Kanae’s butterfly hairpin which Kanao wore breaks in battles, Shinobu exacts her revenge on Douma while her efforts against Muzan are also in motion and then she reunites with Kanae and her parents in spirit, and Kanao wears Shinobu’s butterfly hairpin in the final showdown and then she makes Shinobu the surprise hero in the surprise final battle to save Tanjiro. It was a really long night, and a really short, busy life.