Ikoma

Ikoma (生駒, Ikoma) is the main protagonist and a young steamsmith who formerly made a living in Aragane Station working with steam engines. He and his friend, Takumi developed a steam weapon called "Tsuranuki Zutsu" which Ikoma believes is the best way to fully destroy a Kabane. However, during a Kabane attack on Aragane Station, he got bitten and was forced to use metal (bolted onto his body) in order to control where the infection occurred. Fortunately, Ikoma was fast enough for his brain to resist the infection, so he became Kabaneri. Boarding the Koutetsujou in hopes of arriving to Kongoukaku to investigate the Kabane.

Appearance
Ikoma is a bespectacled young man of average height and build. He has golden-brown eyes, and messy, light blonde-green hair. After being bitten by a Kabane, his hair partially turns white, his skin takes on a pale green tint, and his eyes turn red. His glasses are missing a lens on the left frame while the lens on the right frame is tinted green.

Ikoma often wears his steamsmith's uniform, which is considerably torn after his first encounter with the Kabane. In order to stop the Kabane virus from spreading to his brain, he bolts and brands a shoddy harness to his body, which encompasses his right shoulder and some of his right torso. He also wears a tight collar around his neck, which helps keep the virus at bay.

Personality
Ikoma is generally portrayed as a calm, intelligent, driven, foolhardy and determined but guilt-ridden individual with a serious demeanour. He maintains a light-hearted sense of humour which is shown whenever in the company of his closest friend Takumi.

Ikoma's greatest desire is to exterminate the Kabane from existence, this nature is fueled by the death of his beloved sister Hatsune which he witnessed five years ago, this event left him emotionally traumatised and remorseful over, henceforth Ikoma dedicated his life to discovering a method in which to fight back against the Kabane; his social standing, however, caused him to occasionally be mocked and looked down upon by others, most notably the Bushi.

His sister's memory serves as a moral code and reminder for him to never flee from a situation from which he can help and thus Ikoma displays a great level of loyalty, courageousness and selflessness. He maintains a keen sense of justice, prioritising the lives of others before his own, this trait, however, occasionally places him into precarious (and even fatal situations.) Ikoma also bears a strong sense of honour in spite of adversity, which clashes with his inherent desire to help others, this nature ultimately serves as an act to redeem himself for his past failure as well as 'To become someone he can be proud of'.

Originally upon boarding the Koutetsujou, after indirectly revealing his identity, Ikoma became heavily distrusted by the fellow members, most notably Kurusu and for a considerable period of time he is forced to remain in confinement. However after dealing with the threat of the invading Wazatori he finally gains their respect and is accepted onto.

Ikoma is also a tinkerer, born from his work with steam engines. He develops the Tsuranuki Zutsu with help from Takumi, which is the only known weapon that is able to pierce the caged heart of a Kabane in a single shot.

History
Ikoma was born in Hinomoto, to unnamed parents (during the 3rd year of the Kabane infection), where he grew up alongside his loving sister named Hatsune. One day the siblings found a pair of rocks located near a lake where Ikoma initially offered his sister to have both of them, however, Hatsune insisted that they kept one each as 'good luck charms'. Around the age of 12, the station Ikoma and Hatsune resided in became overrun by the Kabane which resulted in all the adults fleeing in fear, where tragically through the devastation his sister was caught by the Kabane. Powerless to do anything, Ikoma fled and desperately sought for aid from terrified citizens only to be pushed aside. By the time Ikoma returned, he discovered that Hatsune had been killed by the Kabane and had already begun to reanimate, Ikoma tearfully weeped over her corpse and apologized for his cowardliness before using a suicide bag in order to prevent her from attacking him.

This event left Ikoma emotionally traumatised and this he developed a deep hatred for the Kabane, upon where he personally strived to discover a way to fight back against them and to berid the Kabane of their existence from the world in order to avenge his sister’s death and to ultimately redeem himself for his failure.

At some point later, Ikoma journeyed to Aragane Station where he became employed as a Steam Smith where he helped to repair and maintain several Hayajiro, it was during this period where he met and befriended several other steam smiths including Takumi whom became his closest friend, alongside Kajika. Throughout the following years, Ikoma began researching and developing on a specialized weapon named the 'Tsuranuki Zutsu', which he personally designed to pierce through a Kabane's heart cage.

Aragane Station Arc
Ikoma works on his unperfected steam gun, during a trial his gun fails to penetrate a bar of metal which is almost as hard as a Kabane's heart cage.

He goes to his job as a steamsmith and meets his friend and partner involved into developing the steam gun and researching Kabane, Takumi. Soon, Ikoma tells Takumi how the trial went and Takumi suggested adding more explosives. Shocked when he realizes he was missing a step (after Takumi pointed it out), he wants to go back home to finish the steam gun. Princess Ayame Yomogawa arrives and asks for her father's steam gun to be fixed. The chief calls Ikoma, and he is called "hero" by his workmates. The princess asks if he wanted to be a hero, he replies he just hated running away. The Koutetsujou arrives at the station early because the Kabane had invaded another station. Ikoma does his work cleaning and repairing the Koutetsujou, and collected a Kabane carotid artery and explained that it was "rare to get such a good specimen". He first saw Mumei here. A person is accused of being bitten by a Kabane and Ikoma exclaims that the man is not to be killed but he is to be put under supervision according to the law. Ikoma is beaten by the Bushi, the man is killed and Ikoma is thrown in jail.

Mumei visits Ikoma and asks him if he knew if the man was a Kabane. Ikoma explains that humanity cannot escape fear.

The Fusoujou arrives carrying Kabane, it crashes and enters the station with Kabane. As the Kabane invade the station, Ikoma escapes from his cell and goes on to finish his steam gun. He uses his blood as bait. He manages to kill a Kabane but he is bitten and the virus starts to infect his body. Ikoma strangles himself using a belt and a machine to stop the virus from reaching his brain. A part of his hair is changed from light green to white after the process to stop the virus (possibly due to the stress caused to his body by this event).

Takumi, arrives at Ikoma's workshop and Ikoma explains that his weapon was a success but he was bitten by a Kabane and he didn't transform into one. They travel to meet up at the Koutetsujou. They are stopped by guards. Two Kabane appear and Mumei kills them near the Koutetsujou. Mumei asks Ikoma if he had changed his look, sniffs him and tells him that he was not normal. He is stopped by Kurusu and Mumei tells them that he was not a Kabane.

Another horde of Kabane attack the Koutetsujou. Ikoma saves some civilians from a steam pipe, he stops the pipe with one hand and is able to withstand the heat. A Kabane is able to penetrate the metal door, Ikoma fights off the Kabane with his new weapon. He kills the Kabane then realizes he exposed the inside of his robe which shows his  heart as that of a  Kabane's. Kurusu shoots him and he is thrown out.

Later, the switch bar for the bridge is not working so they needed to use the manual bar to lower the bridge. The only problem is that it is outside and swarming with Kabane. Ikoma fights off the Kabane, getting bitten multiple times without minding the pain. He lowers the manual bar and the Koutetsujou is able to move on.

He cries due to frustration, while Takumi throws out a hook in order to rescue him, he chooses to ignore it. Mumei jumps off the Koutetsujou towards Ikoma's side and hooks up his feet. He is soon given a suicide bag by Kurusu. Mumei explains that he is neither a Kabane nor a Human. Instead, he had become a Kabaneri.

Journey to Kongoukaku Arc
Ikoma attempts to leave the train, stating that he could incidentally turn everyone into Kabane, Mumei kicks him and says that he has a mind of human, while his body is that of a Kabane. While Mumei reveals her goals of arriving in Kongoukaku, Ikoma tries to interrupt, only to be beaten by Mumei once more. After having a nightmare, Ikoma suddenly wakes up to Mumei in the boiler car, who explains why she needs to get to Kongoukaku, while requesting the former to be her guardian. Ikoma protests, while Mumei mockingly kicks him across the room. He follows her to the other room, as Mumei claims that she smelled a Kabane.

While speaking with Mumei, Ikoma explains his past and his sister's death, blaming himself for not being able to save her. They are then attacked by a group of people, who are stopped by Ayame. While Mumei calmly leaves, Ikoma is left with Ayame, who attacks him with her knife, questioning his motives. Ikoma says that he has made a vow not to run away, as his purpose in life is to destroy all Kabane. Ayame backs off, asking if the group still doubts his true affiliation. After having a brief conversation with Ayame, Ikoma succumbs to his wounds due to the blood loss and hunger, pouncing on her, mindlessly attempting to bite her. However, Kurusu comes in and angrily berates him about his actions, pointing his gun at him. The conflict is soon stopped by Mumei, who says that the wave of Kabane is closing in.

As the locomotive itself is overtaken by a certain number of passengers, other steamsmiths are also thrown into a room where Ikoma and Mumei are in, as civilians accused them of sympathizing with Kabane, planning to detach their car from the rest of the fortress. However, a large group of Kabane led by Wazatori attacked the locomotive, slaughtering the passengers nearby. Ikoma recalls his sister's death while watching the Wazatori murder a woman. Ikoma suggests he and Mumei exit the service hatch and chase after the Kabane.

The group went onto the top of the locomotive, discussing on how they will eliminate the threat. As Mumei informed the steamsmiths about the name of the cave, they concluded the time of their ambush. As Takumi gives Ikuma his gun, they fight through the small horde of Kabane infesting the top, while nearing the main threat. Mumei gradually got exhausted, prompting Ikoma to face the Wazatori alone, placing her trust in him. Ikoma is weakened due to his need of blood, pleading for someone to help him in order to kill the rampaging Kabane. Ayame came out of the car, forming a contract with Ikoma by offering her blood in exchange for his protection. Ikoma ambushed the Wazatori from above, pointing his gun at the Kabane's heart, ultimately killing it. The group celebrated their win.

Ayame declared that Ikoma and Mumei will travel with the group.

Yashiro Station Arc
While en route, engineers developed a new gun (with the help and assistance of Ikoma) based on Ikoma's piercing gun. Ikoma also made an enhanced experimental version of katana that has its durability increased (currently untested). After the Koutetsujou is blocked by a crumbled metal construction, Ikoma formed a plan with the rest of the personnel on how to unblock the passage for the locomotive. However, Mumei disagreed with Ikoma's plan to use the longer way to the crane in order to avoid the Kabane.

Later on, Ikoma visited Mumei and questioned why she doesn't want to aid them. After a short argument, Ikoma warned her not to attack the Kabane nest directly. As they arrived near the crane, Ikoma noticed Mumei rushing towards the center of the nest, and chased after her. In the crane, Ikoma angrily looked at Mumei for not following the plan, and activated the machine. After a large herd started engulfing the construction, the Bushi warned Ikoma about retreating to the locomotive. Ikoma goes after Takumi and takes control over the crane himself, in order to protect the two. He noticed an exhausted Mumei going towards the Kabane to fight them alone, and rushed to her after she got overpowered and kicked off the crane by a Wazatori, stopping the crane in the process.

As he carried her to the passage underground, they get crushed by crumbling rocks from the damage done to the construction.

They survive the incident, with Ikoma being able to move, and Mumei being trapped under rocks. Ikoma tried to free Mumei, although unsuccesfully. A large group of Kabane attacked the two, and Ikoma went off to fight the herd in order to protect Mumei. After rescue arrived, Ikoma and Mumei are recovered and soon reunited with everyone at the train.

Ikoma is once again tasked to control the crane in order to move the damaged tower, which was the initial plan, and succeeds. However, the Koutetsujou is targeted by a Fused Colony, and after a failed shot, Ikoma and Kurusu went out to face the Kabane approaching the vehicle. When the Fused Colony is defeated, Ikoma saves Mumei from a fall and retrieves her back to the car.

Human
As a Steam Smith, Ikoma possesses an efficient knowledge regarding the basis of mechanics and engineering (as benefitted from his time spent working on various steam engines.) His abilities are paramount, being able to personally design and construct his own specialized weapon named the 'Tsuranuki Zutsu' - a weaponized bolted rivet gun, designed to pierce directly through a Kabane's heart cage. This becomes his signature weapon in which he proves proficient in its usage.

Ikoma has proven to be resourceful and intuitive, as demonstrated after his encounter with a Kabane despite becoming bitten, he was able to quickly redirect and prevent the virus from spreading around his body by utilizing various pieces of equipment located around his smithy. He has also exhibited a reasonable knowledge of lockpicking.

Despite never having received any form of training, Ikoma has proven to be a capable combatant, being able to fend off against numerous of the Kabane, along with being able to fight against several trained Hunters and even being able to hold his own against Biba (despite being outmatched by his skill.)

Whenever under pressure, Ikoma has demonstrated to posses a high pain tolerance as proven through slicing his wrist, cauterizing his bite wound (with a burning piece of wood), alongside enduring several bolted metal restraits attacthed to his body.

Kabaneri
Increased Strength and Heat resistance: Compared to a human, as a Kabaneri Ikoma's strength and heat resistance are greatly increased. He is able to hold and bend a scalding hot pipe with his bare hands with no indication of pain, as well as return it to its proper place effortlessly. He is also able to easily defeat a Wazatori, a much more powerful variation of Kabane.

Enhanced Durability: Ikoma's body is considerably stronger and more resistant, as he was able to take a bullet to the chest and still fight multiple Kabane.

Enhanced Regeneration: His wounds evidently regenerate much more quickly, his vitality making him capable of recovering from a wound that is fatal to humans.

Immunity: After being turned into a Kabaneri, Ikoma develops immunity from Kabane bites. This is proven by him being bitten several times throughout the series without turning into a Kabane.

Kabane restriction/inhibitor: Like Mumei, he wears a restraint around his neck in the form of a metal harness. It is possible that Ikoma could potentially be more powerful without his restraint as well. However, as a half-Kabane, he requires blood to unlock his full potential and risks himself into turning to a Kabane without drinking any blood.

Takumi
Takumi is Ikoma's closest friend. They are often seen together, and as fellow steamsmiths, they developed a gun that is able to pierce a Kabane's heart. Ikoma puts great trust in Takumi, uncovering his bite wound to him.

Mumei
Mumei is a Kabaneri turned Nue, and like Ikoma, had lost all of her biological family to the Kabane. it is clear that Ikoma cares deeply for her. When Takumi questions whether Ikoma sees Mumei as a replacement of sorts for his late sister, Ikoma, shocked, claims that he does not see Mumei as his sister, and that the only thing the two share in common is maybe their short stature. Despite telling Takumi that Mumei is a "brute", a flashback reveals that he sees an innocent and kind spirit in Mumei like that of his sister[8]. This leads him to be protective of Mumei, even though she is a better fighter than he is. Biba, having recognized this kindness since he took Mumei in, deems it her only weakness (one he willingly overlooks).

When Ikoma learned about Mumei's birth name, Hozumi (which means heaps of rice), he decided to turn Mumei back into a human, kill all the Kabane and take back all the stations and rice paddies - just so that he can "fill her belly with rice", just like how Mumei's mother wanted to when she bestowed her that name. This promise between the two soon becomes his reason for living. In Episode 11, Ikoma is broken after thinking that Mumei no longer remembers that promise, but after learning that there is a possibility of bringing her back, Ikoma shows that he is willing to die to fulfill his promise to Mumei and finally "become a man he can be proud of".

Trivia
生駒
 * Ikoma is the first person in the series to be seen turning into a Kabaneri.