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 which seems standard of Kara.

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. He is also a powerful Fire Release user, able to completely incinerate an individual, supposedly overcoming a target's regeneration capabilities. Using the Summoning Technique, Kashin can summon a giant boiler toad to crush an enemy.

Versus Momoshiki Arc
In the days leading up to the Chūnin Exams, Kashin Koji seemingly attacks a disgruntled Katasuke Tōno in his lab as part of a conspiracy with Ao to place the man under a mind-controlling genjutsu in order to extract intel for Kara.

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 Konohagakure.

He later speaks to Ao on a train and instructs him to retrieve the vessel that Kara lost, leaving him with a case filled with the needed information and weapons to carry out his mission. After Ao failed in his initial encounter against Team Konohamaru to find the vessel, Kashin, confronted the latter, displeased by his recent sloppiness. As he questioned Ao's resolve at fighting fellow ninja again, Ao bluntly stated that any compassion he had died a long time ago. Content with the answer, Kashin reminded him of his mission to retrieve the target and warned them about Team Konohamaru preparing an ambush on him and left.

Witnessing Ao's defeat at the hands of Boruto, Kashin summons a large toad to crush both. Ao manages to save Boruto before succumbing to the toad's weight, making Kashin wonder if this last act was an impulsive decision or if Ao wanted to die a noble death. He then introduces himself to Boruto.

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