Koji Kashin

is a clone of Jiraiya that was created by Amado Sanzu for the purpose of killing Isshiki Ōtsutsuki. A former Inner of Kara, he was in charge of the sector on the outskirts of the Land of Fire.

Background
Koji was created as an alternate plan against Isshiki after Amado's plan for using augmented cyborg Outers was shut down by Jigen. In the anime, Koji witnessed Kawaki being confronted by Garō and Kawaki unconsciously activated his Kāma and blasted Garō.

Personality
An enigmatic man, Koji has a very stoic and straightforward nature that follows a no-nonsense view. Arrogant as he may appear, he has consistently shown himself to be a very rational and perceptive man. He is very calculating and methodical in his approach, able to immediately determine the truth of the situation before him and likewise able to determine how things will most likely play out. At the same time, he isn't flawless, as he wasn't able to anticipate that Isshiki Ōtsutsuki saw through his deceptions. He is also shown to very persuasive, able to convince the very stubborn and loyal member of Kara, Delta, to follow his lead.

When introduced, he showed absolute loyalty to Kara, willing to assassinate a fellow colleague on orders from his leader. He also appears to have an interest in Boruto Uzumaki. Ultimately, his loyalty to Kara was but a façade for his goal to take down Isshiki Ōtsutsuki, showing a very patient nature. He views this goal as siding with humanity. Even more, whereas his previous subservient nature to Kara made him look down on the shinobi lifestyle, reprimanding Ao for clinging to such, Koji is shown to be rather proud of being a shinobi himself, stating outright he is fine work working as a tool as that is part of being a shinobi.

In the anime, seemingly having inherited some of his genetic source's love for Konohagakure, he openly feels nostalgic for the village, smiling at the thought of it. Like Jiraiya, Koji is resolute until the end. Despite being made to realise that Amado never meant for him to go beyond killing Isshiki's vessel, Koji remained confident of himself, believing he can defeat the Celestial Being singlehandedly. Even when he retreated from his battle with Isshiki, Koji still retained a defiant look rather than a look of fear.

Appearance
As a clone of Jiraiya, Koji's likeness is identical to the Sannin, albeit he is physically in his prime compared to his template, having no wrinkles and his hair is straight unlike Jiraiya's spiky hair. Koji is a tall man with shoulder-length white hair that he keeps the top of in a topknot, leaving the rest to flow freely. He also sports trimmed beard along his jawline and black markings on the corner of his eyes, extending downward and ending to his cheeks which resemble the Roman numeral "Ⅱ". He also has a small wart on left side of his nose. He also noticeably wears a mask which conceals the top-half of his face, along with the black hooded robe with maroon lining that seems standard of Kara. Beneath his robes, during his meetings with Kara and Ao, he wore a long maroon coat with a row of buttons on the right side; during the meeting with Kara it was left unbuttoned, but while meeting with Ao the buttons were fastened and he wore a belt over it. Later, when confronting Team Konohamaru, he donned a shorter maroon jacket with black lining and straps with buckles, as well as a brown tactical belt and armour on his upper right leg and a pouch on his left hip.

Abilities
As a clone of one of the Sannin and an Inner of Kara, Koji is regarded to be a complete monster in terms of power and ability, with his abilities being viewed as superhuman. He was able to easily overpower and defeat one of Konohagakure's top jōnin. In the anime, he was viewed as a very troublesome opponent by the Sixth Hokage. He appears to be among the stronger Inners, as he easily defeated and killed Victor and was confident he could defeat Delta. Even Isshiki Ōtsutsuki himself acknowledged Koji as a very capable man. He was capable of killing Isshiki's vessel after he was severely weakened and even held his own against Isshiki himself.

Physical and Chakra Prowess
Koji has had his body modified with Scientific Ninja Tools by Amado. He has blazing speed, able to catch an opponent off guard from a distance even while they face him. He possesses great stealth skill, as he snuck up on the more experienced Victor unnoticed and also moved around Konohagakure upon infiltrating it completely unnoticed. He is highly skilled in taijutsu, easily countering all of Konohamaru Sarutobi's melee attacks and simultaneously implanting techniques on the latter without him knowing. He could even compete with a heavily weakened Jigen, able to counter and exchange blows with him very well. He is extremely resilient, able to survive having an arm destroyed, his torso and legs crippled, and still had enough strength to summon a toad to escape. Likewise, Koji has tremendous chakra control, able to perform techniques with only a single hand, despite his mangled state. He also has equally strong and large enough reserves of chakra to use Sage Mode.

Ninjutsu
Koji uses ninjutsu from Konohagakure, and has inherited his template's mastery and skill-set at a greater scale. He can create multiple shadow clones and seamlessly switch places with them to avoid detection. He is one of few to use the Rasengan, easily matching Konohamaru Sarutobi's own usage, and can even use the Ultra-Big Ball Rasengan. He is very knowledgeable of other people's techniques, as he understood the nature of the Konohagakure Sensing Barrier and how to bypass it. He can also manipulate his hair to attack and defend against his enemies.

Koji's skill in shurikenjutsu can effortlessly hit a fellow Inner of Kara before they can react. He can use Space–Time Ninjutsu, able to enter Kara's Ten-Tails' dimension at will and carve seals to summon eternally burning natural fire. Koji can summon toads to aid him, ranging from summoning tiny toads that act for surveillance, act as a medium for his techniques, giant toads to crush targets, and also perform the Reverse Summoning Technique. Uniquely, Koji has also summoned naturally occurring phenomena, such as flames, from their origin. He can use fūinjutsu to paralyse targets within his erected pillars. He can also produce a smokescreen from his body and launch sticky oil from his mouth.

Nature Transformation
Koji can utilise Fire and Earth Release. He has shown great mastery in using Fire Release; he can use True Fire of Samadhi, that from hitting targets through small mediums, will cause the victim to spontaneously combust, strong enough to overcome a target's regeneration capabilities and never extinguish. He can also launch a barrage of fireballs from his mouth and even imbue his fist with fire to consume his target in flames upon striking. With Earth Release, he can morph the ground in the area into sinking mud to ensnare his foes. He can also use Yin Release to project an image of himself to talk with people from a distance.

Senjutsu
Koji can use Sage Mode. Unlike his template, Koji can instantly access it with a perfect balance of charka and natural energy, emphasised by gaining toad-like irides with black pigmentation around his eyes and no other physical alterations. Through his senjutsu skills, Koji enhanced his physical abilities and sensory perception to the point of being able to catch a strike from Isshiki Ōtsutsuki and temporarily keep him at bay before quickly countering. His ninjutsu is also enhanced, able to use techniques such as Sage Art: Five Fire Gods' Fan of Flames, to the point of temporarily pressuring and surprising Isshiki with the overwhelming amount of flames.

Versus Momoshiki Arc
In the anime, during the days leading up to the Chūnin Exams, Koji ambushed Katasuke Tōno to find out who was stealing data for Kara using genjutsu on a scientist. Having learned that Momoshiki Ōtsutsuki was defeated, he assumed Naruto Uzumaki was the person responsible for Momoshiki's defeat.

Kara Actuation Arc
In the anime, Koji was present when Jigen called a meeting with the Inners, informing them of the destruction of one their facilities in Amegakure set by an Outer.

Ao Arc
As a part of a secret plan, Koji and Amado conspired to betray Jigen and ultimately kill him and Isshiki Ōtsutsuki, and caused the airship transporting the "vessel" to crash. Upon their organisation losing their "vessel", Koji discusses the matter with the other members of Kara. Immediately after their meeting, Koji approached fellow Inner Victor to assassinate him, and mocked him for not noticing his presence. After impaling him with a kunai, Koji used True Fire of Samadhi and incinerated Victor under Jigen's orders to punish the former for conspiring against Kara, before thinking about Konoha. Shortly later, he approached Ao on the Thunder Train, and instructed him to retrieve the "vessel" Kara lost, and provided him with the weaponry for the mission. After Ao fought Team Konohamaru during his search, Koji approached him, and questioned Ao's resolve to fight the fellow shinobi again. Stating his compassion has long since gone, Koji was content with his answer and warned him about their enemy preparing an ambush for him before departing.

Having watched Boruto Uzumaki defeat Ao, Koji summoned a toad on top of the pair, which crushed Ao to death. Refusing to enlighten them about Kara, he paralysed the team using fūinjutsu. Overcoming the technique, Konohamaru faced Koji alone, during which he attempted to strike Koji with his Rasengan, prompting Koji to counter it with his own. Complementing his opponent on his skill, Koji engulfed Konohamaru in flames, which triggered Boruto's Kāma activating. Shocked to see it, Boruto subconsciously absorbed Koji's techniques. Thanking Boruto for showing him it, Koji decided to leave, before complimenting Mitsuki for stopping [[Sarada] from recklessly pursuing him.

Kawaki Arc
Shortly after, Koji observed Team 7 making contact with Kawaki, before being joined by Delta. Realising she didn't have faith in him recovering the vessel, Delta informed him that she invited Garō to partake in the mission. When Boruto revealed his Kāma to Kawaki, Koji questioned what would happen next. After Kawaki killed Garō and fainted from overheating, Koji convinced Delta against getting rid of the Konoha-nin and retrieve Kawaki then and there, feeling that Boruto having a Kāma merited further observation before taking action, also arguing that the crash blimp made it inevitable that the world would learn about Kara before bowing to their power. Later, Koji and Delta arrived at the main gates of Konohagakure to retrieve Kawaki. While Delta stated that it would be difficult infiltrating, Koji told her to stay put before entering the village without setting anything off and began searching for Kawaki. Once inside, Koji summoned a small toad to find Kawaki, who he eventually found taking shelter in the Seventh Hokage's home. Deciding it was too dangerous to engage Naruto Uzumaki, Koji decided to continue observing for the time being.

He watched as Boruto and Kawaki make the Seal of Reconciliation, and Boruto was taken aback by a vision, an event which also made him instantly heal his hand. Koji was greatly intrigued by this, wondering if it was a byproduct of the Kāma and worried if Jigen had the same ability. He then noticed Delta propelling herself through the village and to Kawaki, noting how out of control she is. After Delta was defeated by Naruto, Koji praised Naruto's strength but noted not even he could defeat Jigen, considering the Kāma, like the one in Boruto's hand the only way to do it. As Koji continued to monitor Kawaki, he expressed concern on how it had been a while since Delta had been defeated yet Jigen had still not made a move, believing it to be unlike him especially as he had definitely learned about Boruto's Kāma and Naruto's personal protection of Kawaki from Delta. To his shock, Jigen teleported to Kawaki's location through the Kāma he gave him and wondered if he could do that anytime then why would he assign a mission to retrieve Kawaki in the first place. As Jigen sensed the presence of Koji's toad, Koji dispelled it as he realised from the beginning Jigen had suspected him and had been baiting him to learn his true motives, rather than Koji probing Jigen's movements.

In the anime, Koji snuck a toad through the portal to continue watching the fight between Naruto, Sasuke Uchiha, and Jigen. He watched as Naruto and Sasuke were able to pressure Jigen to go all out and despite their defeat, Jigen's body was left overtaxed and breaking down. Afterwards, Koji was approached by Boro via genjutsu. He revealed to Koji the spy toad of his that he recovered from the crashed airship, accusing Koji of being the traitor. Koji however did not deny it was his toad, explaining that Jigen suspected trouble during Kawaki's transfer and had Koji keep an eye on things. He also noted that Jigen had recently entered Konohagakure and spotted Koji, yet did nothing to him. As Boro accepted Koji's explanation, annoyed at hitting a dead end on his investigation, he ended the communication. Later, Koji snuck into a village archive, looking for data. However, the archive's digital files only went as far back to after the Fourth Shinobi World War. Older data remained only on physical scrolls in another site. Koji began manipulating the Konoha-nin into thinking he was trying to escape while making his way to the other site. His efforts were thwarted by Kakashi Hatake, who saw through his deception. He forced Koji to retreat, deciding the scroll was not crucial to his plans.

Later, Koji decided to return to the base. Upon arriving, he learned from Amado that Jigen was still not even at 10% capacity. Also learning that others Inner were not at base, Koji decided he would use this opportunity to kill Jigen. Amado collected the essential for him to continue his work, and Koji summoned a toad. Delta arrived, intent on not letting them leave without Jigen's permission. Koji offered to deal with her, but Amado merely issued a shutdown command, making Koji wonder if his modifications contained similar measures. Koji gave him directions to follow, and reverse summoned his toad, with Amado, to the outskirts of Konoha, and proceeded inside the Kara facility. As Koji approached Jigen he secretly had a small toad act as a camera to relay the discussion to Amado. Quickly, the discussion became tense, as Jigen revealed he knew that Koji and Amado sabotaged the blimp, letting Kawaki escape. As he asked Koji what his true goal is, Koji attacked him, proclaiming he was created solely to destroy Jigen.

Jigen called him a tool for dedicating his life to one job. Koji however stood resolute, proudly declaring it as the way of the shinobi. Once luring Jigen into his trap, Koji summoned a massive wall of flames, knowing that the Kāma could not absorb naturally occurring flames void of chakra. As the flames killed Jigen, it forcibly activated the final stage of his Kāma and resurrected Isshiki Ōtsutsuki through his vessel. As Jigen was not fully compatible as a vessel, Isshiki's resurrection was unstable. Isshiki used his boost in power to instantly shrink and disperse the flames. Eventually, Isshiki's assault destroyed Koji's mask, leading Isshiki to learning of Koji's identity. Struggling, he activated Sage Mode. Upon realising that Sukunahikona required seeing a target, he managed to catch Isshiki off-guard with his Ultra-Big Ball Rasengan. Isshiki used Daikokuten to summon massive stones that crushed Koji's left arm and flank. Realising he could not win, Koji summoned a giant toad, which swallowed him and teleported away.

Trivia

 * Koji Kashin shares his name with a folkloric magician believed to have lived in the late Muromachi period, though his historicity is debated. He is often depicted as a white-haired, bearded, elderly man in robes, and is said to have used his illusions to deceive and defraud prominent rulers such as Oda Nobunaga.
 * In the manga, Koji assassinated Victor without a known reason. In the anime, it was an order from Jigen for Victor's unauthorised actions in the Land of Valleys and for betraying Jigen and copying Kawaki's data from Kara's databanks.