Goemon Ishikawa XIII, the thirteenth-generation descendant of historical bandit Ishikawa Goemon, was conceived to inject Japanese cultural elements into the series. Initially planned as a descendant of Nezumi Kozō, that concept was later repurposed separately. Early in the Lupin III franchise, he appears as Lupin III's adversary, hired to assassinate him or guard secrets like his sword's formula. After consistent defeats, he allies with Lupin, recognizing his skill and choosing to learn from him, cementing a partnership based on mutual respect and periodic loyalty challenges. His personality blends fierce pride in martial ability with unwavering dedication to Japanese traditions. He exclusively wears Japanese attire, consumes Japanese cuisine, and practices cultural customs, rejecting Western alternatives while meditating during downtime. This stoic exterior cracks around seemingly innocent women—whom he trusts impulsively, often to his disadvantage—and children, whom he instinctively protects. He falls prey to scams offering spiritual enlightenment and can be bribed with Japanese food, reacting with explosive anger if it's wasted. Modern technology unsettles him, causing struggles with devices like smartphones or car pedals across adaptations, though his adaptability fluctuates. A master of Kenjutsu and Battōjutsu, Goemon wields the razor-sharp Zantetsuken (or Ryusei). This sword slices through virtually anything—bullets, vehicles, buildings—yet he typically avoids killing by severing weapons or clothing instead. After such non-lethal strikes, he declares his signature phrase: "I have cut yet another worthless object." He also excels in Jujutsu, Aikido, and Karate, disabling groups unarmed. Failures like damaging Zantetsuken or succumbing to distractions trigger deep shame, often driving him to solitary meditation or training retreats. In *The Columbus Files*, he joins the hunt for the weather-controlling Columbus Egg. The plot revolves around Fujiko Mine's amnesia after memorizing the Egg's location, leading Lupin's team to recover her memories and secure the artifact. Goemon's secondary role features eccentric, humorous behavior that enriches dynamics between Lupin, Jigen, and Zenigata. His interactions emphasize traditionalist values and bewilderment at modern tech, aligning with his franchise portrayal. While focusing on Fujiko and Lupin's relationship, the special reinforces Goemon's loyalty during justice-driven missions or ally protection.