Mark Twain appears in the 1985 anime film The Dagger of Kamui as a supporting character based on the historical American author Samuel Langhorne Clemens. He is depicted with brown hair and cyan eyes, and his nationality is American. In the story, his occupation is that of a writer, reflecting his real-life profession. Twain is encountered by the protagonist Jiro while the latter is traveling through the American frontier on his way to Los Angeles, heading for Santa Catalina Island in search of Captain Kidd’s hidden treasure. His role in the narrative is brief but notable: he engages Jiro in conversation and expresses a keen fascination with Jiro’s endurance and resilience, drawing a parallel between Jiro’s determined journey and his own understanding of human perseverance. This moment serves to highlight Twain’s characteristic curiosity and wit, and it provides a moment of cultural exchange and reflection within the broader adventure. The character does not undergo any development across the film, as his appearance is limited to a single encounter, and he does not possess any special abilities beyond those of an ordinary person of his era. His motivation during the scene is rooted in his natural inquisitiveness as a writer and observer of people. The relationship between Twain and Jiro is that of a brief, amicable acquaintance, with Twain offering a perspective that underscores the thematic weight of Jiro’s quest.