Akiko and Tanjirou are set to wed in a week's time.
The girls were overjoyed to hear this news, and despite the intense need to focus on the upcoming battle against Muzan and the rest of the Upper Moon demons, they still allowed a bit of happiness and hope to float into the estate.
"What kind of dress will you wear Akiko-san?"
"Will the wedding be held here Akiko-san?"
"What about all the food Akiko-san?"
Sumi, Kiyo and Naho bombard the poor girl with questions, yapping at her heels like puppies in an attempt to squeeze some juicy information out of her.
Akiko is on her way to the lab near the Ubuyashiki estate, where Tamayo and Shinobu are working as well. Unfortunately, the only reason why she's back at the Butterfly estate is because she had to pick up a change of clothes.
Even she could smell how bad she was.
"It will be a small wedding," Akiko says to the girls. They begin to protest loudly begging and pleading for the event of the century. That Oyakata-sama would spend the money for this big wedding and that all the Hashira would help and the girls want to wear their best kimonos.
But Akiko can see that they just want a nice break from the impending nightmare.
She crouches down at their level, smiling as warmly as Tanjirou does, "Look girls, when you find the love of your life, you won't care how you marry them. You just want to stand at their side with the people that love and support you both. The fact that Tanjirou and I can even marry soon is a miracle, but I understand your enthusiasm."
The girls pout lightly, but there isn't anything they can do.
Instead, Kiyo pipes up quietly, "Well what would your dream wedding be if you could have anything?"
"Akiko wants a Western dress, with traditional Japanese food. She wants to be married at my childhood home in the mountains, but is willing to marry me anywhere on the spot if she has to. She wants a bouquet of flowers and the sake ceremony, and a close friend or family to officiate. Isn't that right my love?" Tanjirou sneaks up on his fiancee, and Akiko blushes a fierce red.
Because despite how this dream wedding of her's is something she talked about as a child, every detail remains true today. And Tanjirou still remembers it all.
"W-Well yes... But we can just exchange rings and do the sake ceremony instead..."
"No way! I've been waiting to marry you my whole life, and you only deserve the best of whatever you wish!" Tanjirou kisses her atop her head as she covers her face.
The girls squeal in delight before running off, satisfied with the answers they received. Akiko turns to swat Tanjirou against his chest, but stops when she sees how horribly beat up he looks.
"What happened?!" Akiko screeches, tugging Tanjirou into her office.
Tanjirou laughs weakly, fully caught and in trouble. He then explains his rough and tumble with the Wind Pillar, and Akiko knows that on the other side of this moment, Miyuki is harshly berating Sanemi.
Akiko purses her lips when dabbing Tanjirou's cuts with a cotton ball of alcohol. She knows better than to reveal the troublesome siblings' history, and her focus should be on Tanjirou instead.
Tanjirou asks her how Nezuko is doing, and how the experiments are going. But Akiko is sworn to secrecy, and Tanjirou understands. So they talk about the Pillar training instead, about how Zenitsu was also involved in the scramble and how Tanjirou has been speeding through all the training (likely due to favoritism, but also because Tanjirou is such a quick learner.)
Akiko does her best to divulge information of her own. She says that progress is slow, and that she's only at the Butterfly estate to freshen up. That she thinks of him every night before she sleeps, and is delighted to receive letters from him every day.
When it's time for the two to part ways, Tanjirou holds her face in his hands and runs his thumbs over her cheeks. Akiko smiles with glee, and she continues to smile into the kiss that they share.
—-
Akiko and Tanjirou see each other sooner rather than later.
The last Pillar training is with Himejima, and demon slayers are slowly starting to trickle onto his training grounds. Akiko's starting to get reports of hypothermia and burns, so Shinobu and Tamayo allow her to stay on the grounds and make sure to treat the demon slayers.
"Are you sure I'm no longer needed?" Akiko asks, slowly packing her bag on the off chance that they change their minds. But Shinobu and Tamayo are the ones ingesting the poison, and they've already completed the solutions. It's just a matter of continuing to ingest poison and double checking Nezuko's antidote.
So without further ado, Akiko hops onto a kakushi and speeds off to Himejima's training grounds.
Upon arriving and seeing demon slayers walking over flames, she immediately shuts it down.
At the very least, Akiko was allowed that much jurisdiction. However, even if demon slayers were under the waterfall for 10 hours in one day, Akiko was not allowed to start treatment unless their bodies turned blue and the strength of the falls caused their bodies to give out.
Since Himejima's training is right after Shinazugawa's training, she spent most of her time welcoming the new demon slayers to hell and fixing their wounds before throwing them under the waterfall. Upon seeing her fiance, Akiko waves wildly before running to greet him.
"Wow, ignoring me?" Zenitsu sideeyes Akiko, and Akiko continues to do so.
"Tanjirou! You're already looking a lot better than the other day!"
"SO YOU ARE IGNORING ME!"
"Ugh, you're here?"
"It really wouldn't hurt you to be nicer to me y'know."
"Funny. Be prepared to be dumped into the river."
Akiko isn't even kidding either. Himejima's explanation alone is enough to knock Zenitsu out, and Himejima mercilessly tells Tanjirou to dump him into the river. During this time, Akiko sees that Inosuke has fallen unconscious under the falls, and deploys a few demon slayers cuddling up against the rocks to get him out.
A minute of CPR later and Inosuke is back to his crazy self, but Akiko employs him to catch some fish for her instead. She's seen him pass out under the falls for a few days in a row now, but this is the longest he's gone.
Tanjirou, being the proud son of a coal burner, quickly starts a fire while Akiko skewers the fish. She has her own lunch packed away, a few riceballs made by the girls at the Butterfly Estate. The two work in tandem, talking easily between each other about the other Pillar training and the new friends they've made.
And while everyone talks amongst themselves, Akiko stays silent by Tanjirou's side. They warm each other up by the fire, Tanjirou talking animatedly with a fish skewer in one hand, and holding Akiko's hand in his other.
Akiko was planning on spending another night at Himejima's training grounds, but she receives a message from Oyakata-sama, and is whisked away.
She doesn't arrive alone. Miyuki and Chiyo are also there, Ayame left behind at the Butterfly Estate. Akiko knows this must be serious if Chiyo didn't bring Ayame. She's sitting by Oyakata-sama's side, doing another routine checkup and mixing some medicine on the side, and he does his best to relay a new mission to the girls.
"Muzan has been tracking us. I believe you three are the best for this job," he says, and Akiko raises a brow. She's just a doctor, and she doesn't know how else she can help, but she doesn't question them.
At the very least, the three get to work together.
Oyakata-sama doesn't have any information, just that his foresight knows that the battle is drawing near and that Muzan has found a way to slowly track all the demon slayers, and is getting closer to finding his estate.
The girls regroup at the Butterfly Estate to figure out their next move. Akiko's shut the door to her office, telling all the girls that they mustn't get close to the room, and they nod their heads obediently.
"There's no way Muzan is tracking us himself," Chiyo starts, "He's too high up for something like that."
Akiko quirks a brow, "So you think he has some random demon do it?"
"No," Miyuki shakes her head, "It's got to be an Upper Rank. The lesser demons don't have strong enough blood demon arts. And he'll want to keep this demon close to him. So it has to be Upper."
The girls all purse their lips. An Upper Rank is less than ideal. For starters, they don't know what kind of demon they're dealing with. How powerful this demon may be, and what they can throw at the girls. The other problem is Akiko. Should they come into contact with the Upper Moon, Akiko has no way of defending herself.
In the end, they decide to go looking for the person with the most information. Tamayo.
Tamayo is still working in the lab with Shinobu when the three girls arrive. Shinobu and herself are discussing the four poisons when Akiko knocks on the door, and Shinobu lets the girls in with a smile. Tamayo has to step out of the way when a sliver of light falls through the doors, but it goes quickly once the door has been shut.
"The Forest and Ice Pillar. To what do I owe the pleasure," Tamayo says.
"Secret mission from Oyakata-sama. But I have a feeling you can help us," Chiyo smiles. Akiko divulges the details of their mission, and Tamayo sits quietly as she listens. Miyuki and Chiyo offer their theories, but by the end of it Tamayo is shaking her head.
"I'm sorry ladies. I have no connection with Muzan anymore. That was severed hundreds of years ago. I have no clue as to what demons are within his rank," she says. The girls deflate, their first and only lead being a deadend.
"However," she starts, and the three perk up simultaneously. Like three dogs that heard 'treat'. "I do believe this may be the perfect time to test one of our battle strategies." Tamayo churns her head to one of the hallway doors, and Akiko can see that it is barely ajar. And behind it, she can assume, is Yushiro.
Tamayo calls the demon forward, and he walks in with a slight grimace, though obedient nonetheless.
"Yushiro, please give Akiko the seals."
In Akiko's hand is a small stack of papers with a red symbol on them. They're about the size of Akiko's hand, and each symbol is the same. Akiko recognizes them from Tanjirou's stories, the one he recounted to Akiko a few months ago as the two caught up over their past endeavors.
"In order to command the Demon Slayer Corps from a safe location, Oyakata-sama asked us to devise a plan. Yushiro's Blood Demon Art comes in handy for situations such as these, and it's quite strong because he comes from my blood, and my blood comes straight from Muzan. Gather as many crows as you can. They will be your eyes, Akiko."
The girls leave with instructions, and Yushiro promises not to mess with their mission (for the sake of Tamayo-sama). They start by giving their own crows the seal, and Akiko quickly understands what Tamayo meant by 'they will be your eyes.'
Because they almost are.
Akiko can see treetops and farmland from one crow, and a bustling town with loud merchants from another crow. Her brain almost stopped when she switched crows, the blast of information being too much for her brain to handle. Chiyo is quick to peel the seal off when Akiko cries out, Miyuki placing her cold hand over Akiko's forehead to help soothe it, but Akiko stubbornly slaps the seal back onto her forehead.
It take a couple days, but Akiko gets used to the crows. Chiyo and Miyuki cook and train together, taking turns cradling Ayame. Akiko sits on the engawa, shifting through crows while the Pillars wait patiently for some sort of news. Akiko's crow army slowly grows, but she starts to grow frustrated when she sees no suspicious sign of Muzan.
"I feel like I'm looking for a needle in a haystack," Akiko mutters, and the two girls look at her weirdly. Akiko brushes it off ("Western saying.") but they can understand that she's starting to get antsy.
"Y'know, I don't think Muzan is going to let us come to him." Miyuki says, and Akiko nods.
"You're right. Muzan is, unfortunately, too smart for that."
"So how do you think he's tracking us?" Chiyo shrugs, giving Ayame a bottle of milk for the night.
Akiko pauses for a second before her eyes grow wide, shimmering like the stars under the moonlight.
"He's tracking us! We don't have to find him, he's already looking for us! We let him find us, that's how we find him."
The two Pillars look at each other with a triumphant smile, their hands already on their katanas, and they run off to be bait. Akiko immediately sends a crow after each of the Pillars, also calling for Aoi to take Ayame since Chiyo just dumped the baby on her ("Wait you know I can't hold babies-")
It takes all night. Chiyo and Miyuki have both gotten pretty far from the Butterfly Estate, both on opposite sides of the mountain. Two crows follow closely behind, silently observing, silently watching.
Chiyo is the first to encounter the eye. Akiko almost misses it, a small thing, really. Chiyo is jumping a bit too fast through the forest, but Akiko says, "Stop," and the crow caws in return. Chiyo halts immediately, her ears tuning in for any off sound.
The crow perches itself, looking down and around. And then Akiko sees the nasty thing.
"To your left," the crow caws, and Chiyo almost mistakes its words. But she flashes forward, using her Forest Breathing and cutting down two trees beside her. Then Chiyo sees it too, and she jumps forward to stab the eye with her katana. It wriggles around before lying limp, and Chiyo holds it up to the crow for Akiko to observe.
In the eye, Akiko reads, "Upper Four," and a chill runs down her spine. "Come back," she commands the two, "and kill any eyeballs you encounter along the way. I don't think that's the only one. And if I'm right, we have a lot of work cut out for us."