|“||I'm repulsed by weaklings. They make me vomit.||”|
As a Demon, Akaza took the form of a muscular young man with skin so fair that appears bright green-tinged white, decorated by a mass of thick blue lines. The lines on his face curved through each of his eyes from below his ears to over his temples, another blue line running from the center of his hairline to the bridge of his nose, with two more lines running around his neck, three others branching off the lower one to his torso. The center line ran directly down his chest to halfway down his stomach, and the other two branched off to the sides over each side of his chest to join the two other lines, this same three line pattern there also repeating around his waist. On his arms there were lines running down the front of his shoulders that ran into to two more, which went around his biceps, before continuing to run down to his wrists, below which it could be seen that each of his fingers is also dark blue with an orange fingernail, his toes also sharing this unusual appearance. Akaza had short, bright pink hair that fluffed out around his head, and inward-tilting yellow eyes with pink eyelashes and blue sclera that looked somewhat like cracked glass, the kanji for "Upper Moon Three" etched into their irises.
He wore little, only sporting a short, sleeveless dark purple-pink haori that was cut off at his waist, left open to expose his chest, that was decorated by a square pattern on his back. Below this, he sported a pair of baggy white pants that he rolled to just below the knee with a blue rope belt to secure them at his waist. Akaza prefers to go barefoot, but wears a chain of large round pearls around each of his ankles.
During his human days as Hakuji, he had the same hair, just colored black rather than pink, and pale blue eyes with unusually-colored pink eyelashes. He was also very muscular as a human, and, on each of his forearms, he bore three black criminal tattoos.
He wore a dark blue-gray yukata.
Akaza was a strong, stubborn and impulsive Demon who enjoyed fighting, especially strong Demon Slayers. He looked down on anybody he deemed weak, but genuinely respected those who were strong in his eyes, regardless of their race. Once he met someone he deems strong, he demanded to know their name, and would not stop until he finds out; he remembers all the names he's committed to memory as tribute to their strength.
Akaza had a deeply-rooted psychological need to become stronger, and did not get along with his fellow Upper Moons due to him seeing them as his rivals. He was especially antagonistic towards and even appeared jealous of the two Upper Moons above him, Doma and Kokushibo, lashing out at Doma and vowing to kill Kokushibo. Even after being beaten down and beheaded during his fight against Tanjiro Kamado and Giyu Tomioka, he stubbornly held on and continued to fight despite not even knowing why he wanted more power.
As a human, Hakuji possessed the same stubborn personality with a big heart and resilience. He valued others more than his own well-being, and hated himself for having a life "full of empty words and promises." Even after becoming a Demon and losing his memories of his human life, parts of Hakuji's memories influenced Akaza's decisions; he refuses to eat women, despite knowing it would make him stronger if he did so. His hatred of weak, cowardly people stemmed from a corruption of his human memories, where a rivaling dojo poisoned his dojo's well because they were never able to beat his.
Hakuji was born and raised in the slums to a sickly father he deeply loved. In order to pay for medicine, Hakuji pickpocketed from people in town, but was caught three times. The magistrate beat him and marked him with tattoos, threatening to cut his arms off the next time he was caught and calling him a "Demon Child". When Hakuji returned home after his third beating, a villager informed him that his father, having heard of his arrest, hung himself. In the letter he left, he stated he wanted Hakuji to live a full life and didn't want to take medicine if it was earned by dishonest means.
With his criminal tattoos and no home to return to, Hakuji was eventually banished from Edo. Devastated by the loss of his father and enraged at this society they lived in where he couldn't afford his father's medicine, he picked fights with people and beat them up. One day, after nearly killing seven adult men in a village, he was approached by Keizo, the owner of a dojo in the village. Annoyed by the man's cheerful demeanor, Hakuji challenged him to a fight, but was defeated with ease.
Keizo took him in so he could nurse Koyuki, Keizo's sickly daughter. Her mother, her previous caretaker, drowned herself due to stress and Keizo had to work handyman jobs to keep them afloat, so Hakuji was tasked with tending to her. Already accustomed to tending to his father, he had little trouble tending to her, though he found it awkward whenever she burst into tears. One of those times, unbeknownst to him, he had indirectly motivated her by telling her that "there will be a next year" to see the fireworks.
Three years later, she was in good health and could stand and do chores. He continued training as Keizo's pupil of the Soryu style, and the dojo began to grow. One day, Keizo offered Hakuji to take over the dojo—and take Koyuki as his bride, to Hakuji's surprise and embarrassment. He agreed, silently vowing to protect both of them, even at the cost of his own life. At a festival, Koyuki told him of her past, asking if he was really okay with the proposal, to which he reaffirmed his vows to her, promising to protect her for the rest of his life.
Tragically, this vow was short-lived. He took a short trip to visit his father's grave and inform him of his marriage, but quickly realized something was amiss upon his return. A student from the dojo informed him that their rivaling kenjustu dojo, which had always sought Keizo's land for themselves and prevented him from getting any students until Hakuji's arrival, had poisoned the well from where Koyuki and Keizo drank water from. The two died shortly after drinking that water while Hakuji had been away.
Enraged, Hakuji killed all sixty-seven members of the rivaling dojo with his bare hands, pulverizing them to the point where their corpses were no longer recognizable. This incident caught Muzan Kibutsuji's attention and, though he was disappointed to find it had been a human rather than a Demon who'd done such a gruesome act, he decided to make Hakuji one of the Twelve Demon Moons. Hakuji, with nothing left to protect and having lost his will to live, accepts and becomes the demon Akaza.
After becoming a demon, he lost his memories of the time he became a human, with only one single desire to become stronger despite not knowing the reason why he wanted to become strong. Despite this, as noted by Doma, he refused to ever eat or harm women. Due to his strength, Muzan only dispatched him for special missions, such as searching for the Blue Spider Lily.
Abilities and Powers
As he was the holder of the 'Upper Moon Three' title, Akaza possessed a tremendous amount of strength, having been able to defeat Kyojuro Rengoku, the Flame Pillar, and also several past Pillars, according to what he stated. Later, he was able to fight and overhelm both Tanjiro and Giyu, even when they were both using their Demon Slayer Marks and Tanjiro was using the Dance of the Fire God. If not for Akaza losing his will to continue fighting, he would most likely have killed both of them. In further testament to his might, he was capable of becoming the holder of the Upper Moon Three title and the fourth strongest Demon in the series without killing or eating any women, which would've hindered his growth as a Demon drastically. It can be safely assumed that Akaza would've been much stronger and likely of a higher Demon Moon rank if not for him limiting his killings only to men.
- Enhanced Strength: At the age of 11, he was able to lay waste to grown men in a fight and at the age of 18, he was easily able to decapitate, dismember and mutilate 67 armed adult kendo masters with his bare fists, to the point that even Muzan thought that it was a Demon who performed these feats.
- Enhanced Endurance: Prior to being transformed into a Demon, Akaza (Hakuji) demonstrated superhuman endurance at the age of 11 as he endured beatings that could make a grown man go numb (100 beatings) thus earning the title of "Demon Child."
- Soryu Style (
素流 式Soryū Shiki?): A barefisted martial arts style taught to him by Keizo when he lived with him and took care of Koyuki. He used it to kill the kenjutsu students with ease and probably was the inspiration of his Destructive Kill Style used when he became Akaza.
- Master Hand-to-Hand Combatant: Akaza is an extremely powerful and skilled unarmed fighter, using it as his main style of fighting. Even though his head was cut off by Tanjiro, Akaza's hand-to-hand prowess remained just as powerful.
- Immense Speed: Akaza was extremely fast, as shown during his fight with Kyojuro when Tanjiro states that they were moving so fast his eyes couldn't follow their movements.
- Immense Strength: Akaza possessed tremendous physical strength, as shown when he easily breaks Giyu's sword in half with a single side punch despite the latter swinging his blade down. he was able to easily destroy Doma, Upper Moon Two's, head with his arm and easily pierce through Kyojuro's stomach. With his Blood Demon Technique, he was capable of causing crater on the ground by punching it.
- Enhanced Regeneration: Akaza possessed incredible regeneration. He was able to regenerate from slash wounds inflicted by Tanjiro and Rengoku and even lost limbs inflicted by Giyu with little effort. During his battle against Giyu and Tanjiro, his regeneration evolved even further. He was able survive even after having his head cut off and then was able to regenerate a new one, a feat only Muzan had accomplished beforehand.
Blood Demon Technique (
- Destructive Kill (
破 壊 殺Hakai satsu?): A type of Martial arts, likely adapted from the Soryu Style hand to hand combat that Akaza had mastered as a human now further enhanced with his abilities as a Demon.
- Compass Needle (
羅 針Rashin?): Deploying a compass underneath him with numbers from 1 to 10. It can detect all incoming attacks through sensing battle spirit.
- Void Style (
空 式Kūshiki?): Punching the air, Akaza creates a powerful multishot shockwave range attack.
- War Style (
乱 式Ranshiki?): Punching in front of him, Akaza creates large shock waves that fly forward.
- Obliteration Style (
滅 式Messhiki?): An explosive forward jump followed by a punch that was able to go through Kyojuro's Purgatory attack.
- Leg Style (
脚 式Kiyakushiki?) - Techniques where he uses his legs to attack
- Cap Tip Slice (
冠 先 割Kamuro saki wari?): A reverse, rising axe kick he can use to attack behind himself.
- Flowing Light Flash (
流 閃 群 光Riyūsengunkō?): Multiple, rapid straight kicks that each produce powerful shockwaves.
- Ring of a Thousand Flying Planets (
飛遊 星 干 輪Hiyūseisenrin?): Rapid, flowing rising kicks that hit an opponent from below.
- Cap Tip Slice (
- Dual Layered Demon Wick (
灼 骨 炎 陽Shiyatsu kotsuenyō?): Akaza punches rapidly with both arms at once, each producing powerful shockwaves.
- Crush Style (
砕 式Saishiki?): Techniques that involve crushing attacks from above.
- End Style (
終 式Shiyūshiki?): Powerful techniques. Presumably Akaza's strongest techniques.
- Akaza was the only Demon of the Twelve Demon Moons who refused to eat or kill women, and was given special permission to do so.
- Akaza's Technique Deployment ability forms the shape of a snowflake; possibly due to the influence of his fiance (Koyuki's name contains the kanji for "snow").
- Many of Akaza's attacks and techniques are named after fireworks, a reference to his promise to Koyuki to see the fireworks.
- Akaza is the only member of the deceased Upper Moons who encountered the people he knew in life while disappearing. There are two members of the Twelve Demon Moons who have been shown experiencing this, the other being Rui.
- Akaza is the third Demon who was able to overcome Muzan's influence over himself by willing himself to stop regenerating and die, the other two being Tamayo and Nezuko Kamado.
- (To Giyu Tomioka) "Elegant!! This is finely crafted swordsmanship! Splendid! Give me your name! What is it!? I want to remember you!"
- (When Muzan Kibutsuji offers to turn him into a Demon) "... I don— I... just don't care any... more..."
- (About himself) "But for over a hundred years, I kept pointlessly murdering over and over again. Yet, at the end of the day, it's just a pathetic, comical, uninteresting story."