Mitsuri Kanroji/Synopsis

History
Mitsuri was born with an unnatural strength and a strange hair color, which lead to her being seen as a freak and left unable to get married. She was judged by her mother for this inability, and so dyed her hair in an attempt to fit in more with other girls. This didn't prove useful, however, as she was still rejected for being clingy to her betrothed.

She then encountered Kagaya Ubuyashiki, who told her to reject normalcy and embrace who she was. Because of this encounter, she joined the Demon Slayers and used her skill and ridiculous strength to rise to the status of Hashira. She has also adopted her idea of finding a man stronger than her to marry, but this didn't work out because she was much stronger and more skilled than all of her fellow members, with the exception of her fellow Hashiras.

Rehabilitation Training Arc
Shinobu Kocho noted that Tanjiro was on trial, while Mitsuri thought about the potential killing of Nezuko Kamado with trepidation. When Obanai demanded to know what punishment Giyu Tomioka would receive for his role in their subordinate's mistake, Mitsuri praised his persistence, as well as Giyu's aloofness. Later, she questioned whether or not they should make a decision in Tanjiro's trial without Oyakata-sama's input, suggesting they wait until he arrived. Shortly thereafter, she praised Sanemi Shinazugawa's increase in scars and Shinobu's sternness with the former's actions. The Love Hashira's expression of praise quickly turned to horror as Sanemi stabbed Nezuko, but just as quickly turned to mirth when Tanjiro headbutted the former, much to her mortification.

Demon Train Arc
When Mitsuri received news of Kyojuro Rengoku's death, she was horrified and shocked.

Swordsmith Village Arc
When Tanjiro Kamado reaches the hidden Swordsmith village, he loudly thanks a kakushi for safely taking him there. Mitsuri is shown visibly naked, her breasts and underparts covered, in a hot spring, stating that she heard the echo of the thank you, and that her heart was pounding. Later, after Tanjiro speaks to the chief, the Hashira sees Tanjiro and come running towards him, Tanjiro warning her to be careful, or her breasts will fall out of her kimono. She cries and tells him that she asked the name of a boy, and he ignored her, even though she is a Hashira (In an extra, it is revealed that he did not speak to Mitsuri because he was too stiff and nervous from her cuteness.). After she tells Tanjiro she has no more "good energy" from the hot spring, he states that dinner is almost ready, and that they might have used matsutake mushrooms. Kanroji is immediately cheered up and walks away happily singing a song.

Tanjiro, Mitsuri, and Nezuko eat dinner together, and Tanjiro is amazed by how much she can eat. She says she didn't eat that much as usual, but Tanjiro is encouraged anyways to eat a lot to become stronger. He tells Kanroji that the boy she met before was Shinazugawa Genya, and Mitsuri realizes that Genya is actually the Wind Hashira's little brother, even though Sanemi said he did not have any siblings. She considers that the brothers do not get along, and that it's tragic since she gets along well with all five of her siblings, guessing that the brothers are "just scary." Tanjiro becomes worried for Genya since hasn't come to eat his dinner. While playing with and hugging Nezuko, she says it seems like he is not going to come, and that he told the Swordsmith Village's townspeople that he will not eat at all. Tanjiro says he will bring Genya leftovers, and Kanroji agrees that that is a great idea.

Mitsuri sings while holding Nezuko's hand, and Tanjiro suddenly asks her why she joined the Corps. At first, she is embarrassed and hesitant to tell him but confesses that she did it to find a man who would marry her for the rest of her life. She blabbers on about how girls like men who are stronger than them and can protect them. Tanjiro is surprised and speechless, having the same reaction any other person who heard her reasoning had had.

The three are looking for Genya when a kakushi comes up to them and tells Kanroji that she is needed at the workshop for the finishing touches on her nearly-finished sword. She is sad to leave the Kamado siblings, and Tanjiro volunteers to escort her out, but she replies it is fine because she might have to leave in the dead of night. Tanjiro reluctantly stutters, but Mitsuri interrupts him. She gives him a kind smile and tells him that they might not see each other alive the next time they meet but to do what they can. She says that his survival against a battle with an upper moon is a great learning experience that is very valuable and compares to five to even ten years of extreme training. She states that he is much stronger than when they last saw each other at the trial, and she completely supports the Kamado siblings. Tanjiro thanks her and announces that he couldn't have won without Uzui's help, that he still has a ways to go, and that he will work harder to defeat Muzan. Kanroji seems to suddenly remember something after listening to him, and, after glancing at the kakushi patiently waiting for her, whispers in Tanjiro's ear that there is a secret weapon in the village that can make him stronger, telling him to go look for it. She then leaves with the kakushi and says goodbye to the two. Tanjiro has a large nosebleed from her whispering in his ear.

Later into the arc, as Tanjiro, Nezuko, and Genya continue fighting Hantengu's different forms, and Muichiro battles Gyokko, Mitsuri returns to the Swordsmith village from her own district, which is very close by, trying to hurry and save the people in danger. She races toward the main houses where villagers are being attacked by Gyokko's mutant demons and swiftly cuts them down. Mitsuri finds a humungous, mutant fish-demon beginning to crush the chief of the village after already killing his demon slaying guards. A bloody bystander tries to get up to save him, but Mitsuri tells him not to get up because his internal organs are most likely wounded. She uses Breath of Love 's First Style: Shivers of First Love to easily kill the demon and says that her heart "will never throb for those who hurt people with sick jokes." Tecchin falls from the mutant-fish's grasp, Kanroji safely catching him. Her eyes tear up as she tries to see if he is still alive, and the chief comically says that he must be in heaven since he is being held by a cute girl. She seems surprised and calls him a little perv as another wounded villager asks her to take his hand since he fell on his head too, Mitsuri instantly asking if he is okay. The bystander is immediately relieved.

When Tanjiro is swallowed by one of Zohakuten's tree dragons, Mitsuri slices the creature's head in half, carrying Tanjiro on her back safely. She squeals at the monster's size and questions what it is, then asks Tanjiro if he is alright, and that it's a good thing that she made it in time. After putting Tanjiro down, she tells him to rest and doesn't hear him try to tell her that the demon is the Upper Moon Four. She confronts Zohakuten, telling him in a disciplinary way that his "pranks" have went too far, and she will be taking Nezuko and Genya. Zohakuten tells her to shut her mouth, that he only takes orders from one person, and calls her a harlot. Kanroji is visibly in pure shock from his rude comment, thinking that he looks as young as her little brother, even though most demons are much older than they seem.

The hatred, emotion clone lashes at Mitsuri with '''Resonance Bolt of Death. Tanjiro calls out to her and, without hesitating, she uses Breath of Love Third Form: Lovely Kitty Shower''' against it. She declares that she is getting angry, and, though Zohakuten may look like a child, his actions are still unforgivable. Tanjiro is shocked at how well she suppressed his bolt, and the demon seems a bit impressed by how she cut through his attack itself.

Mitsuri continues to battle against Zohakuten. She dodges the crushing hit of the maple leaf-like fan and uses Breath of Love 's Second Form: Anguish Inducing Love. One of the tree dragons throws another attack from its mouth, but she evades it with Sixth Form: Kitty Paw Love Breeze. The demon realizes that she is too fast and is keeping up with his attacks, making him have to use a technique. He sends Blood Demon Technique: Karmic Wood of Avici, lashing out many wooden dragons. Mitsuri becomes a bit nervous at how wide-ranged it is and questions if she can get past it. She strikes back with Fifth Form: Wavering Attachment - Messy Nails. She gets past the attack and comes very close to Zohakuten. The demon opens his mouth, confusing Kanroji, though she brushes it off and goes for his neck. Tanjiro yells to her that he is not the real body, and he will not die if his head is cut off. The Love Hashira realizes her mistake and is fiercely hit by Zohakuten's Maddening Screech. She loses consciousness and slumps before the Upper Moon. Tanjiro screams out to her as Genya and Nezuko try to break free from the wood and help her. The demon is flabbergasted by how Kanroji maintained her body shape and withstood his head-on attack. He notices that she might've tensed up all her muscles before his attack, and that she is no ordinary girl, her strength not matching her looks. He thinks she has "high-quality meat" but decides to crush her brains and skull in, pulling back his fist. As he is about to kill her, her entire life flashes before her eyes.

She wakes up as Tanjiro, Nezuko, and Genya fall on her and pull her away from Zohakuten. Tanjiro exclaims that they have to protect Mitsuri because she is their ray of hope and only chance of winning, and that none of them are going to die. The demon launches another quick attack, but Mitsuri cuts through it all. She cries as she thanks everyone and says sorry for messing up, even though she is a Hashira. She says she won't let any of her friends die, the demon slayers are her precious home, she will not lose to "evil people", and that it's time to get serious.

Mitsuri remembers everyone who has been a supporter in her life and states she will protect everyone. She runs at the demon, slicing through his wooden dragons. She thinks to her herself that she needs to get her blood circulating and increase her heart rate to become faster and stronger. Zohakuten tries to hit the siblings and Genya, who are trying to find the main body, but the Love Hashira stops him. The Upper Moon notices how much faster she has gotten and wonders how she did it. Then, he sees some sort of birthmark close to her clavicle that he hasn't seen before, resembling a demon crest. He throws another attack, but Kanroji continues to cut it, making him extremely annoyed that he can't kill the others. He knows that she won't last forever and that, sooner or later, she will run out of stamina.

Right as Kanroji feels as though she is going to die, Tanjiro kills the main body, and Zohakuten crumbles to dust. Mitsuri falls to the ground and cries tears of joy, exclaiming that they must have cut Hantengu's head off. She runs up to Tanjiro, Nezuko, Muichiro, Genya, and Kotetsu and pulls them into a group hug. She cries and rejoices that they won, and that it is awesome. She wails that they're alive and thanks the gods with Nezuko repeating after her.