A kakuja (赫者, red one, kakuja) is a kind of ghoul with a transformed kagune that clads the ghoul's body. Though it is rare, it can occur through repeated cannibalization. When a ward has a higher ghoul to human ratio, cannibalization is more common due to turf wars and limited food supply.
Sometimes, the transformation is incomplete, and such individuals are called half-kakujas (半赫者, han kakuja).
It is said that through cannibalism, a ghoul absorbs Rc cells, and this increases the concentration of Rc cells within a ghoul's body. If the concentration becomes high enough, it may trigger a mutation and lead to the formation of a new kagune.
A kakuja can further evolve by continuing to cannibalize their kind. For instance, while the One-Eyed Owl had a human-shape and size before its disappearance, it eventually developed into a much larger and monstrous form during the Anteiku Raid in the 20th ward.
The transformation seems to be affected by psychological factors as Ken Kaneki's kakuja takes the form of a centipede, resembling the Red-headed Chinese Centipede Yakumo Oomori (Yamori) used to torture Kaneki by putting it in his ear. Also, earlier Kaneki compared himself to a protagonist of the novel The Metamorphosis who turned into an insect-like creature while picturing a centipede in his mind. Yoshimura's kakuja mask also grew to resemble the One-Eyed Owl's mask, with the former holding the desire to keep attention towards himself and away from the latter for personal reasons.
It should be noted that members of the Tsukiyama family have a birth defect where cannibalism has little to no chance of triggering this mutation in their Rc cells due to consanguineous marriages, thereby preventing kakuja mutations.
Apart from the predatory kagune ghouls commonly possess, a kakuja has a special kagune that clads the ghoul's body and functions like an armor. The kagune amplifies the kakuja's strength or diversifies their abilities, which makes fighting one of them especially hard.
However, using a kakuja kagune is nearly impossible because most users tend to lose their minds while fighting with it. It is unknown why some ghouls are able to remain sane and others are not. One reason may be that all unstable/insane ghouls using kakuja are half/incomplete as full kakuja are not observed to have any problems maintaining control.
It appears that a kakuja kagune can form a mask over the user's face if need be.
|Image||Ghoul||Alias as Kakuja||Forms||Description|
|Yoshimura||Non-Killing Owl||Blades||Ukaku ghouls are known to specialize in long range attacks and can be overwhelmed at a close range. Having cannibalized ghouls during his missions to exterminate other ghoul organizations, Yoshimura has sharpened and developed his kagune to form two large scimitar blades from his shoulders to counteract this weakness. With two large blades, he can cover the distance between his opponents, parry incoming attacks and strike back synchronously. While his ukaku kagune extends from middle to far distances, his Kakuja cuts down those in front; it's almost impossible to escape Yoshimura's reach. Yoshimura's kakuja kagune also forms a mask similar to the One-Eyed Owls with minor differences in the eye hole size and line curves. Unlike most kakujas, he is able to maintain his consciousness.|
|Yakumo Oomori||Jason||Arm (Incomplete)||After escaping the prison, Yamori cannibalized in the 13th Ward and became a strong, incomplete kakuja. His kagune clads his head and arm which acts like a flesh armor. The armor packs more punch into his attacks by enveloping more flesh into his thorned tentacle and heals his wounds at a faster rate. Since he's an incomplete kakuja, he has no control and fights like a blind berserker.|
|Arata Kirishima||Corpse Collector||Armor||Eating ghoul corpses, Arata developed a full kakuja. Unlike most kakuja, the armor Arata developed seemed to be completely defensive in nature. It consists of metal-like plating that covers the body.|
|Ken Kaneki||Centipede||Tails (Incomplete)|
|After consuming Yamori's kakuja and various other ghouls and their kagune, Kaneki obtained an incomplete-kakuja after his confrontation with Doctor Kanou. Kaneki's kakuja armor are twin centipede-like tails protruding downwards from his back. The massive tails also have sharp talons on the side. In this form Kaneki's kakuja forms a mask that features a hole for his left eye and a bird's beak over the middle of his face. They provide Kaneki with enough power to even overwhelm Shinohara's Arata Proto. As an incomplete kakuja, Kaneki's loses all aspects of his personality when using this form and as a result fights like a psychotic berserker. Due to this, Kaneki only uses his kakuja form in the direst of situations. After consuming Eto's kakuja, his kakuja takes the form of a large arm with a mouth on it, and his mask forms a carapace covering on his entire face. During his final battle with Arima, his third kakuja takes the form of armor encasing his upper torso and arms, as well as being capable of producing koukaku-like blades. In this state, Kaneki is capable of retaining his sanity and making precise calculations in battle. Unlike most kakuja, this one does not sport a mask.|
|Eto Yoshimura||One-Eyed Owl||Behemoth-sized Armor||Due to living in the 24th Ward where the number of ghouls are much higher than humans, Eto had to cannibalize ghouls at an early age and quickly became a kakuja. Like her father, she is able to shape her kakuja kagune into two muscular blades above her shoulders. This increased capability in close range helps her counteract her kagune's weakness. In her full kakuja form, Eto takes the appearance of a large, monstrous creature with her ukaku kagune growing into large spikes protruding from her back, have four large protrusions that are similar to Yoshimura's side blades in his kakuja form, large bird-like feet, and her mask develops four horns and has a single eye in the center with three markings on the left and right cheek and the forehead. In this form, she is nearly unstoppable. Her ukaku kagune is capable of shooting projectiles large enough to overwhelm most seasoned investigators with ease and her physical strength is augmented to the point where she is able to knock out an Arata Proto equipped Yukitori Shinohara and Iwao Kuroiwa through brute force alone. Unlike most kakujas, she is able to maintain her consciousness. So far Kishou Arima, Ken Kaneki, and Nimura Furuta have been the only combatants able to stand on equal footing with Eto in this form.|
|Seidou Takizawa||Owl||Blade (Incomplete)||While Yoshimura possessed a fully realized kakuja, Takizawa appears to possess an incomplete version. The reason for this difference is unknown, but he remains an extremely dangerous opponent even so. The kakuja manifests as a partial mask covering his face, and a massive blade emerging from either shoulder. Its usage appears to significantly degrade his mental state, causing him to ramble nonsense and engage in self-harm. During the events on Rushima and while fighting Tatara, his kakuja seems to be complete. His face is now covered in a large mask of an owl's face and despite retaining his berserk fighting style, he is calmer and more methodical. He no longer rambles incoherently, thinks about his moves, takes down Tomoe and Tatara and manages to regain his composure to converse with Houji and the CCG.|
|Noro||Noro||Mouths||Noro's kakuja is unlike most kakuja. Instead of forming armour, Noro's body transforms into a huge mass of kagune which is covered by large mouths, similar to that of his regular kagune. Noro is unable to move while in this state, as this lump of kagune rages uncontrollably. While in this form, Noro is capable of withstanding a high quantity of firepower.|
|Kurona Yasuhisa||Floppy||Arms (Incomplete)||Kurona's developed a deformed kakuja that consists of four arms and numerous eyes forming over her upper face, combined with scale-like armor covering her body.|
|Tatara's kakuja wraps around his upper body as a bulky armor. Developing two hammer like appendages and numerous eyes forming over his upper face. Through the head, he is capable of breathing fire at 4000°C, easily overwhelming investigators. While in this state, Tatara is consumed by rage.|
|Koutarou Amon||Floppy||Behemoth-sized Armor (Incomplete)||Amon's kakuja is similar to Eto's, both having similar abilities, a single eye on the head of the kakuja and behemoth-sized. However, his is incomplete and his head can be seen emerging from the side of the kakuja's head. It is capable of withstanding damage and shoot massive ukaku projectiles able to break through an enemy's kagune. Additionally, it can merge with Doujima 1/2, creating a kakuja quinque he can use in battle.|