Shinobu was born as the youngest daughter within the Kocho household, living alongside her mother, father and older sister Kanae Kocho. She was raised in a loving and caring household until her parents were slaughtered by Demons right before her and her sister's eyes.

Just when the Demon was about to take the lives of her and her sister as well, they were saved by the Hashira, Gyomei Himejima, who slayed the Demon. Now more determined as a result of the pain and suffering they endured, Shinobu and Kanae both promised to become Demon Slayers to protect each other, as well as prevent other people from enduring the same losses they had to experience. Eventually, after managing to move a boulder, they convinced Himejima to introduce them to a cultivator.

Later in her life, while accompanying her sister Kanae on a trip, the sisters encountered a young girl being led away as a slave on a bridge. Intrigued by her, Kanae took an interest and decided to take the girl back to the Butterfly Estate, against Shinobu's initial wishes. They eventually purchased the girl, named Kanao Tsuyuri, from her master and trained her within the Butterfly Estate to become the next Tsuguko.

At the age of 14, she became the master of the Butterfly Estate in Kanae's place, since Kanae died at age 17. Shinobu coddled the girls of the Butterfly Estate as if they were sisters

Love you all

Take note 📝:It is not my story I'm just representing Kocho Shinobu's life

Shinobu is present when Kagaya Ubuyashiki receives news of the situation unfolding at Natagumo Mountain, and is given the order to travel there and assist the lower-ranked swordsmen. Acknowledging this, the Hashira states that it would be great if everyone could get along, regardless if they are human or Demon, and asks Giyu Tomioka if he agrees.[3]

Much later, Shinobu appears before a heavily injured Zenitsu Agatsuma, greeting and asking him if he is alright.[4] She then suddenly appears behind the daughter member of Rui's Demon Family, inquiring if the strings came out of her palms, wishing the creature a good evening, and commenting on the beauty of the moon that night. Startled, the Demon attacks the Demon Slayer with her strings, but Shinobu dodges them all effortlessly. Drawing her sword, Shinobu dryly comments that this attack means that the Demon doesn't want to get along with her.[5]

Shinobu asks the Demon how many people she had killed.

The daughter Demon quickly begs Shinobu for mercy, stating that she would be killed if she disobeyed Rui. Shinobu, sympathizing with the creature's plight, says that she will cooperate with the Demon if she answers a few of Shinobu's questions, the first of which being how many people she had killed. The Demon's answer is five, but Shinobu assures her that she doesn't have to lie, complimenting her string technique from earlier, and the Demon corrects her answer to eighty humans. Despite the creature's stubborn denial, the swordswoman notes that both of them came from the west side of the mountain, and, on that side, she had found forty of the Demon's cocoons. Shinobu adds that she isn't angry, but only trying to be as accurate as possible. When asked what the point of checking this information is, Shinobu tells the elder daughter Demon that in order for them to be friends and to satisfy those who have died, she will have to endure punishment, explaining in gruesome detail what she had in mind for this, and adding that the creature won't die from it, so there will be no aftereffects.[6]

Shinobu defeats her foe.

Enraged, the Demon attacks Shinobu again, but the Demon Hunter quickly bypasses her, simultaneously landing her Insect Breathing, Butterfly Dance: Caprice attack on the creature. She laments the Demon's poor choice, turning and subsequently watching as the creature collapses. Shinobu tells the creature not to let her guard down just because she can't cut the Demon's head off since, she explains, that she utilizes poison as her weapon instead. Shinobu then introduces herself as the Insect Hashira of the Demon Slayer Corps, stating that, although she may be the only one among her order to not possess the ability to cut off a Demon's head, poison that can kill the creatures is still a potent tool. She then apologizes, realizing that the daughter Demon is already dead and could not hear her explanation.[7]

Shinobu offers to kill Nezuko with a painless toxin.

Shinobu then proceeds to cut open the Demon's silk cocoon, freeing Murata. She asks him if he is alright, and he asks what happened to the older sister Demon, to which she answers that she had killed the Demon with poison from the wisteria flower, commenting afterwards on how lucky he is for only having his clothes melted off by the creature's attack.[8]

She later attempts to attack Tanjiro Kamado and Nezuko Kamado, but her attack is deflected by Giyu. She questions his interference, noting that if he continues this course of action, everyone would hate him.[9] The Insect Hashira asks her fellow Demon Slayer to get out of the way, apologizing to him when he replies that he isn't hated. She then turns her attention to Tanjiro, telling him that he is protecting a Demon and that he should get away from her. The young Demon Slayer exclaims that Nezuko is his sister, causing Shinobu to take pity on her and plan to kill her with a toxin that inflicts no pain.[10]

Giyu restrains Shinobu.

Giyu then instructs Tanjiro to run, which Shinobu notes to be a violation of Demon Slayer's conduct.[11] Later, while being restrained by Giyu's arm, she laments that she had been in the right to come kill Demons and therefore had broken no rules, but noted that Giyu had, asking him what his intent was. Her fellow Hashira remains quiet, prompting her to angrily ask him to say something. Giyu replies that it had all started two years ago, causing Shinobu to note that the length of time was a problem and wonder if he was holding a grudge because she had said he was hated. She then extends a blade from her right shoe and prepares to attack Giyu, only to be stopped by an important message from a Kasugaigarasu which said that Tanjiro and Nezuko are to be restrained and brought headquarters.[12] Later, at the headquarters of her order, the Demon Slayer stood alongside her fellow Hashira in front of a restrained Tanjiro.[13]

She quickly informs the confused youth where he is and that he is on trial for violation of Demon Slayer conduct.[14] When Obanai Iguro points out that Giyu Tomioka had also committed this crime and asks how they are going to deal with him, Shinobu tells him that they will think of a punishment for him later, since she is more interested in hearing Tanjiro's story. She gives the youth some water when he starts coughing, asking him to tell them his story, and also informing him that the water contained a painkiller. Shinobu tells him not to strain himself, as his injuries are still present. She then listens quietly as Tanjiro explains his sister's circumstances.[15]

Shinobu continues to listen to Tanjiro's story, but his dialogue is interrupted by the sudden appearance of Sanemi Shinazugawa, who grabs Nezuko's box. She warns her fellow Hashira not to act on his own, but he ignores her warning, stabbing the trapped Demon with his sword, much to her displeasure.[16] She then watches as an enraged Tanjiro charge the Wind Hashira,[17] and afterwards looked at an apologetic Mitsuri Kanroji.[18] Shinobu's leader, Kagaya Ubuyashiki, then arrived, causing her and her fellow Hashira to bow in respect.[19] Kagaya then asked for them all to accept Tanjiro and Nezuko, surprising Shinobu, who remained silent as her fellows argued over the decision,[20] and as Kagaya's assistant read Sakonji Urokodaki's letter.[21]

The Hashira shocked by Kagaya's revelation that Tanjiro had been in contact with Muzan.

Shinobu continues her silence through even more arguments, but is shocked as her leader revealed that Tanjiro had come into contact with Muzan Kibutsuji. She and her fellow Hashira are then halted from even more debating by a simple gesture from their leader, with the Insect Hashira remaining silent as Kagaya explains more of his reasoning for pardoning Tanjiro and Nezuko.[22] Shinobu then cautions Tanjiro from using any of his breath techniques while pinned by Obanai, as his lungs might explode from the pressure. She calls out his name in alarm as he ignores her advice and tries anyways.[23] After the incident with Sanemi and Nezuko is resolved, she listens quietly as Kagaya explained the dedication of the Hashira to Tanjiro.[24]

With everything resolved, Shinobu suggests they take care of Tanjiro over at her place, instructing the Kakushi to do this, and then waits for Kagaya to start the Hashira meeting.[25] After the meeting has ended, she visits Tanjiro and his friends at the Butterfly Estate, asking them how they are doing and instructing them to begin their Rehabilitation training.[26]