Goemon Ishikawa XIII, the thirteenth-generation heir to the legendary bandit Ishikawa Goemon, upholds his lineage of renegade samurai tradition. His profound Japanese heritage defines him, evident in his kimono and hakama attire, preference for Japanese cuisine, observance of Buddhist and Shinto rituals, and dedication to meditation. He wields the ancestral sword Zantetsuken, a blade of extraordinary sharpness capable of slicing through virtually any substance—from bullets, steel, and vehicles to abstract forces like lightning or even film frames in stylized portrayals. After using Zantetsuken to non-lethally disarm foes by cutting weapons or clothing, he often declares, "Once again, I have cut a worthless object," acknowledging the traditional requirement for a katana to draw blood before sheathing—a rule he frequently circumvents. Initially appearing as an adversary to Arsène Lupin III in manga stories, Goemon targeted Lupin for attempting to steal the alchemical formula responsible for his sword's creation—sometimes adapted as a gold-making formula. His then-lover, Fujiko Mine, exposed Lupin's infiltration attempts, escalating hostilities. Goemon pursued multiple assassination plots against Lupin, employing skilled killers and planting explosives. His stance shifted upon recognizing Lupin's abilities, leading him to join Lupin's group to further his own learning. This allegiance solidified when Lupin facilitated Goemon's revenge against his uncle's killer by sabotaging a legal case, enabling public retribution. Their bond evolved from professional association to genuine loyalty across subsequent media, though Goemon consistently voices annoyance at Lupin's womanizing and occasionally opposes him on moral grounds, vowing his final act toward Lupin will be delivering a deathblow. He shares a notably harmonious rapport with Daisuke Jigen, respecting him as an honorable comrade; Jigen reciprocates this trust, frequently partnering with Goemon on missions. Despite deep distrust of Fujiko due to her betrayals, Goemon collaborates with her when objectives align. His personality blends stoic reserve with fierce pride in his martial skill. Failures, like breaking Zantetsuken in combat or succumbing to personal frailties, trigger profound shame, prompting withdrawal for meditation or intense training. Though typically unflappable, he exhibits vulnerabilities around women, easily deceived by those projecting innocence and reacting with flustered avoidance to overt seduction. Additional weaknesses include susceptibility to scams promising enlightenment, poor money management, and difficulty with modern technology, often needing help to operate devices like smartphones. Masterfully trained in classical Japanese martial arts, Goemon excels in kenjutsu, battōjutsu, jujutsu, aikido, and karate, enabling him to disarm multiple attackers barehanded or deflect projectiles. His background includes ninjutsu instruction under an Iga master, as shown in "Goemon's Revenge," explaining his acceptance of theft despite samurai tenets. He participates irregularly in Lupin's exploits, often operating solo. His past involves betrayal by clan affiliates: childhood friend Kikyo deceived him during a treasure hunt, while fellow trainee Sadachiyo became a rival assassin whom Goemon ultimately killed. In "The Plot of the Fuma Clan," Goemon was engaged to Murasaki Suminawa but ended the engagement after rescuing her from kidnappers, deeming himself unworthy. During the events of "The Blood Spray of Goemon Ishikawa," he accepted a bodyguard assignment for yakuza boss Makio Inaniwa aboard a casino ship. When the mercenary Hawk assassinated Inaniwa amidst Lupin's simultaneous heist, Goemon pursued Hawk out of duty, suffering defeat and a broken sword. Consumed by humiliation, he endured brutal self-punishment to sharpen his senses, unlocking a predictive "sixth sense" allowing him to anticipate opponents' actions. He later decimated the yakuza enforcers sent to punish him and redeemed himself by defeating Hawk in a rematch, severing the mercenary's arm. This arc exemplifies his core traits: unwavering commitment to bushido, resilience forged through self-improvement, and lethal efficacy when honor is compromised. Across various adaptations, design elements like kimono colors and facial structure may shift between series installments, yet his foundational identity as a duty-bound, culturally rooted warrior remains constant. His actions consistently emphasize protecting the vulnerable, especially children, and avenging injustices against them, aligning with his moral code despite his criminal associations.