Koji Kashin

is an "Inner" from the organisation Kara that's in charge of the sector on the outskirts of the Land of Fire.

Personality
Kashin is a straightforward and no-nonsense individual. While seemingly loyal to Kara, he apparently operates under his own views as he was willing to assassinate a fellow colleague. He also appears to have an interest in Boruto Uzumaki.

Appearance
Kashin is a tall man with long white hair which he keeps in a topknot, allowing some to fall to his shoulders, along with a trimmed beard along his jawline. 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. Dark markings can be seen at the corner of his eyes, extending downward and ending at some point beneath his mask. 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
Kashin is noted to not be an ordinary person, and regards himself as an assassin. He showed noticeable stealth skill, being able to sneak up on the experienced elder in his team unnoticed, albeit he did suggest that he was losing his edge in old age.

Ninjutsu
Kashi can utilise Fire Release in the form of True Fire of Samadhi, that spontaneous combust an individual, which is strong enough to overcome a target's regeneration capabilities and never extinguish. Utilising Space–Time Ninjutsu in some fashion, he can summon a small toad, and utilising Summoning: Boiler Toad, he can summon a giant toad to crush an enemy. Kashin is also capable of using the Rasengan, as well as fūinjutsu to paralyse targets within his erected pillars.

Versus Momoshiki Arc
In the anime, during the days leading up to the Chūnin Exams, Kashin seemingly attacked a disgruntled Katasuke Tōno in his Konohagakure lab, as part of a conspiracy with Ao to place the man under a mind-controlling genjutsu in order to extract intel for Kara. Having learned that Momoshiki Ōtsutsuki was defeated, he assumed Naruto Uzumaki was the person responsible.

Ao Arc
Upon their organisation losing their vessel, Kashin discusses the matter with the other members of Kara. Immediately after their meeting, Kashin approaches the elderly man of their group to assassinate, and mocks him for not noticing his presence. After impaling him with a kunai, Kashin incinerates the man, 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, Kashin approached him, and questioned Ao's resolve to fight fellow shinobi again. Stating his compassion has long since gone, Kashin was content with his answer and warned him about their enemy preparing an ambush for him before departing.

Having watched Boruto defeat Ao, Kashin 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 Sarutobi faced Kashin alone, during which he attempted to strike Kashin with his Rasengan, prompting Kashin to counter it with his own. Complementing his opponent on his skill, Kashin engulfed Konohamaru in flames, which triggered Boruto's Kāma activating. Shocked to see it, Boruto subconsciously absorbed Kashin's techniques. Thanking Boruto for showing him it, Kashin decided to leave, before complimenting Mitsuki for stopping Sarada Uchiha perusing him.

Trivia

 * Kashin Koji 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.

pt-br:Kashin Koji