After the events on mount Natagumo, the slayers were told to bring to the headcuarters the slayer with the hanafuda earrings and his sister alive./p
So they did.
And that explains why that same slayer is knocked out in front of the strongest demon slayers in the corps, the hashiras.
A kakushi was trying to get the slayer to wake up, and he succeded after a few minutes.
The slayer woke up with a gasp, he didn't recognized his surroundings, so he was alert. The last thing he remember is running away from another slayer that had a butterfly hairpin, she was trying to kill his little sister Nezuko, something he can't let happen.
So now that he is awake, in an enviroment he doesn't recognize, and with seven people staring menacingly at him... Yeah, it isn't a pretty view.
As soon as his thoughts were coherent, he looked around, looking for the wooden box where his sister is, he couldn't find it anywhere and he was starting to freak out at this point.
That was until another person came into view holding the very same box he was frantically looking around for.
It was a white head with eyes that had a crazed look over them, so Tanjiro didn't trust this guy to not hurt his sister.
And he was right to not trust him, since the next moment he was stabbing the box with his sister inside, she let out a pained groan because of that.
Tanjiro yelled at the slayer to stop, but it went through deaf ears, his sister was stabbed two more times before the white haired slayer made a cut on his wrist and let his blood drop through the gaps he made with his sword in the wooden box.
"Sanemi, that's enough" -said the insect hashira.
"Shinobu is right, the master could be here any moment now" -said the stone pillar.
"Why don't we introduce ourselves to the kid first?" -the love hashira said shyly.
"I'm Rengoku Kyoyuro the flame hashira" -said Rengoku with too much enthusiasm.
"Kanroji Mitsuri, the love hashira" -said mitsuri.
"Iguro Obanai, the serpent hashira" -said Iguro from up the wisteria tree.
"I'm the flamboyant Uzui Tengen, the sound hashira and the god of festivities" -said Uzui while making a pose.
After Uzui presentation, Tanjiro looked at him with a poker face, he wasn't impressed by his antics, and he reminded him of one of his friends that likes to proclaim himself as the king of the mountain.
"Himejima Gyomei, the stone hashira" -Gyomei said while letting some tears fall from his eyes.
"Sanemi Shinazugawa, the wind hashira" -said Sanemi, the one who stabbed Nezuko's box.
"Tomioka giyuu, water hashira" -Giyuu said because he didn't wanted Shinobu to bother him later.
"Kocho Shinobu, insect hashira" -Shinobu said, and right after her introducción she went to the slayer's side to help him talk and sit, since he was sprawled I'm the floor.
"Now, could you so kindly tell us your name and why you are traveling with a demon?" -Shinobu asked him.
"I'm Tanjiro Kamado, and she is my little sister, and I swear that she has not eaten or hurt a single human since she was transformed" -Tanjiro said a little fearfull of the destiny of his sister, he hoped that they won't behead her.
"That she has not hurt a single human? You should think that I'm crazy if you think that I'll believe that" -Sanemi said, he was still holding the box.
Sudently two little girls anounced the arrival of the master Ubuyashiki, making all of the hashiras kneel down in a show of respect, and forcing Tanjiro to do the same.
"Hello my children, how is the weather today?" -asked a man that had a light purple mark covering his forehead.
"!It's sunny outside master¡" -said Rengoku with his usual enthusiasm.
"Glad to hear that, now could you leave the young slayer alone, after all, he has acomplished something you have yet to do" - the master Ubuyashiki said with calm but stern voice, sucesfully getting all the hashira's attention.
"What has he done that we haven't?" -Sanemi and Iguro asked simultaneously, they both were upset by the discovery.
"Well, he was the first slayer lucky enough to meet the new demon king that was appointed two years ago and survive" -The master said, making everyone stare at Tanjiro in astonishment.
After that, every hashira with the exception of Tomioka, started asking Tanjiro questions without giving him the time to answer them.
The master had to intervine by bringing one of his fingers to his mouth in a silencing motion, making the hashiras to shut up the moment they noticed it.
"If you could ask him one question at a time, I'm pretty sure he would be able to answer them, than if you ask them all at the same time" -said the master Ubuyashiki.
They listening to his suggestion, decided to take turn to ask him.
"What is the name of the new demon king?" -asked obanai.
"I don't know, he never told me his name" -Tanjiro answered.
"How did he look like?" -Sanemi asked him.
"Young, he looked between the age of twelve to fourteen, I don't exactly remember his looks, but I do remember that he had crimson eyes" -Tanjiro replied.
"Was he extravagant?" -Uzui asked, making all of the hashiras to look at him with a poker face.
"Hey, I needed to ask" -Uzui told them, he was indignied by them.
"I don't know what you mean by that, but he carried a sword with him, the same with his companion, so... Sure why not" -Tanjiro answered to Uzui's question.
"And before you start asking me his abilities, no, he didn't show a single skill or ability that he may have" -Tanjiro told them before they could even ask the question, he was sure that they were going to ask it anyway.
The hashiras took a moment to contemplate his answers.
"I received this letter from the former water hashira Sakonji Urokodaki, which said that may the sister of Tanjiro hurt a human, he, Tanjiro and the current water hashira Tomioka Giyuu, will kill themselves" -said the master.
This reminded the hashiras of the situation they had earlier, the one they dissmised when they discovered that the slayer in front of them had meet the demon king.
"Master, if I may, I want to test the demon to see if it's true that she wont harm humans" -Sanemi requested, he already had a plan in mind.
"I give you permission to test her" -Ubuyashiki said with a calm voice.
Inmediatly after the master gave him the permission, Sanemi went to where there were shadows to stab the box two times more and then throw it in the floor. The door of the box opened slowly, and a feminine figure got out of it, she stared at sanemi's bleeding arm for some seconds, and then stared at the owner with a poker face.
She knew what he was trying to do, but that wont work on her anymore... maybe if this happened some weeks earlier, she would have been affected by his blood, but since he meet her young lord... yes her lord. He was someone she will respect for the rest of her life for what he did for her, maybe even worship him if she found a way to do it without her brother noticing it.
But the main point it's that now she doesn't have the need to eat humans, all she has to do is sleep, but she still wants to hurt the one that dared to stab her while she was defensless inside the box, so she carefully raised one of her legs, and with a quick moment, she kicked one of Sanemi's legs, making him lose balance and fall to the floor.
"!HMMMN HMMP HMMMNMMP HN!" (!THATS FOR STABING ME!) -Nezuko said to Sanemi, an angry expresion on her face, she then went back to her box, entered it, and then closed the door.
Sanemi's face was red of anger and embarrasement, he couldn't believe that he let his guard down, just because he saw her as a harmless little kid, for a moment he forgot that she was a demon, and while she hurt him, it was payback for what he did to her earlier, apart that she didn't react to his blood at all, so it was enough proof for what the master said.
He still was going to get payback for the humiliation he got infront of the rest of the hashiras, especially to the ones that laughed at his disfortune.
With this, they spared the siblings lifes, and the meeting was concluded, leaving some questions wandering on their minds, but answers they will not get anytime soon... at least not most of them.
A water breather might get them sooner than expected...