Goemon Ishikawa XIII is the thirteenth generation of renegade samurai, a descendant of the historical figure Ishikawa Goemon. He is usually quiet and participates in Lupin III's exploits less frequently than Jigen.
While Goemon might be considered one of Lupin's friends, it starts off more of a professional relationship than friendship. By the Red Jacket Series, Goemon has developed a true loyalty to Lupin, refusing to give away Lupin's secrets when tortured in one second series episode, for example. However, he easily gets annoyed by Lupin's antics, especially Lupin's infatuation with women and Fujiko in particular. He will occasionally oppose Lupin directly when Lupin's jobs or actions do not agree with Goemon's morals. He has even promised that the last act he will take with Lupin is delivering his deathblow. However, Goemon doesn't hesitate to help Lupin in serious situations, and readily assists him any time Lupin works for a just cause. Many theorize that Goemon associates with Lupin out of admiration for his profession, as Goemon's ancestor was a master thief himself.
Goemon has a much more amicable relationship with Jigen. Goemon sees Jigen as a fellow honorable warrior, while Jigen sees Goemon as a trustworthy "foxhole buddy," and the two are frequently paired together during jobs, and usually help keep Lupin in check.
On the odd occasion and increasingly in recent years, Goemon will ally himself with Fujiko, in spite of his distrust of her. As long as their goal is the same and Fujiko makes no attempts to betray him, the two work well together and usually achieve what they seek.
In the manga, Goemon first appears as a very dangerous enemy of Lupin. Lupin attempts to steal Goemon's master's alchemic formula through infiltration of Goemon's clan, but his cover is blown by Fujiko, who happens to be Goemon's girlfriend at the time. Goemon makes many attempts to kill Lupin over the next several volumes, making attempts ranging from hiring assassins as skilled as Jigen himself to entering the service of three martial masters to planting bombs in Lupin's belongings. Eventually, however, he is convinced that he could learn much more working for Lupin than against him, and rather abruptly switches his allegiance. His position at Lupin's side is cemented when Lupin ruins the government's case against the man who killed Goemon's uncle, allowing Goemon to take his revenge as brutally and publicly as he wants without having to break in to prison to do so.
By the events of the second manga series, Lupin trusts Goemon implicitly, and Goemon reciprocates. When a rival of Lupin captures and hideously tortures Goemon, Goemon refuses to even respond to his interrogation except to say that Lupin would find him and allow him to take revenge. Lupin then captures and seduces his rival's wife, and uses the information gleaned thereof to release Goemon, who slays his captor with Jigen's help.
Goemon has two members of his clan appear, but both use their talents to "satisfy their greed" as he once said, Kikyo and Sadachiyo the Scorpion.
In Burn, Zantetsuken!, Kikyo was once a childhood friend of Goemon. When she returned to aid Goemon, she was all grown up. She eventually became his love interest in the movie and traveled with him to get the small dragon figurine, which Lupin found from what's left of the Titanic. Later, Kikyo faked her death so she could turn on Goemon, steal the dragon figurine and side with Chin Chin Chao. Kikyo helped Chao to uncover the secret of the dragon figurine, and used its alloy to make an unstoppable stealth fighter. However, Goemon used his sword and skills to slice the fighter three times at the same spot. It was destroyed and Kikyo fell into the very same spot the Titanic sunk, resting with her grandfather, who stole the dragon figurine in the first place.
Sadachiyo the Scorpion appears in Secret of the Twilight Gemini. He was a highly-trained assassin who was hired by a rogue faction within the Geltic tribe. Causing problems for both Lupin and Goemon throughout the special, Sadachiyo dueled Goemon to the death in the end. Sadachiyo's sword broke the tip of Goemon's Zantetsuken, only for the tip to land in Sadachiyo's back and pierce his heart.
In The Plot of the Fuma Clan, Goemon nearly marries into the Suminawa clan by marrying Murasaki Suminawa, the daughter of one of his instructors. The engagement eventually falls through because Goemon feels he is unworthy of being her husband, though he and Murasaki part on friendly terms.
Goemon Ishikawa XIII is a lifelong adherent of a number of Japanese martial arts, particularly Kenjutsu, Karate, Jujutsu and Iaidō. His training gives him many extraordinary talents, i.e. underwater breath control for diving without an aqualung, and a limited understanding of the supernatural. He can easily best several trained thugs in unarmed combat and catch an arrow or thrown dagger with his bare hands. His trademark skill is near-superhuman fleetness, enabling him to slice bullets in half before they make contact. It should be mentioned that, despite the deadliness of his weapon, Goemon will never take a human life unless challenged to a duel, and even then only if the opponent reveals a dishonorable nature. Although his Zantetsu sword gives him a virtually undefeatable advantage, it is Goemon's talent with the weapon that proves more valuable in a pitched battle. Goemon, like all the Lupin Gang, is also talented at disguises and impersonation, speaks several languages, and is a trained driver and pilot, although he prefers being a passenger rather than taking the driver seat.
Goemon has an extreme sense of pride in his abilities, and when he cannot accomplish a task, usually feels extreme shame and remorse afterward. Breaking Zantetsuken, as he did in a battle with Flinch from Mystery of Mamo, is a common cause of shame. He will also show chagrin when he succumbs to his weaknesses, as when a woman ran off with his sword in Tokyo Crisis. On many of these occasions, Goemon will leave to meditate or further train to rid himself of his weak points.
Goemon's most oft-seen pastime is meditation; during inactive moments, even with potential danger near, he is usually seated on the floor with legs crossed, eyes closed. So deep is his trance that's he's virtually unmovable from this posture. Goemon shows allegiance to Japanese culture as strictly as his travelling and unique lifestyle can allow. He dresses in a hakama, has been seen multiple times wearing a sandogasa, and prefers wearing his hair long and somewhat unevenly cut. His preferred food is Japanese cuisine. He is a firm believer in Buddhism and Shinto. Although he may toast with champagne, his drink of choice is sake. In unoccasional moments, he has been seen smoking a traditional bamboo kiseru. His favorite music is enka, or as Jigen calls it, "elevator music".
Although typically a person of mellow aloofness, Goemon has been seen exploding with frustration, admiring beautiful women, and ...very rarely...screaming in fright. Such out of character moments are usually treated as humorous takes. If Goemon has a true weakness, it is that he's even more weak with women than Lupin is. He readily trusts any woman who seems superficially trustworthy or innocent, often landing him in much trouble. At the same time, he fears sultry women will distract him from his training, and tends to blush or flee when any woman puts him in a less than modest situation.
Goemon also is very bad with money as well as falling for any scam that states will show the path of enlightenment, and constantly charges Lupin for his services in some fashion. What he does with the money is usually a complete mystery. In $1 Money Wars he gives it to the female leader of a cult, who promptly runs off with it.
Commonly thought to be just a samurai, Goemon's Revenge has Goemon visiting his Ninja sensei. This episode depicts him as having had the training of a master ninja, perhaps giving some reason behind his willingness to find thievery as an acceptable practice, in spite of his samurai ways.
Goemon is unique to the series as he was the only character not there from the beginning. Monkey Punch, in an interview featured on the American Dead or Alive DVD release, mentioned he added Goemon later as he felt his comic needed a more Japanese character. There are three different versions of the meeting and joining. Prior to his first appearance in the manga, a character named Koroshi appeared in the first volume. Koroshi strongly resembled Goemon in appearance, but preferred using firearms and was killed at the end of the chapter he was introduced in. Goemon very closely resembles actor Seiji Miyaguchi's character, stern master swordsman Kyūzō, in the film Seven Samurai, down to even Miyaguchi's famous elongated face.
In the original manga, Goemon is targeted by Lupin to steal the secrets of how to make his sword, or in the American release, how to make gold. In later issues, Goemon is sent by his masters to kill Lupin, but after failing many times, he decides Lupin can teach him more and joins his side.
In episode five of the first anime series, Goemon is tricked into going against Lupin by Old Man Momochi, who wants them both out of the way so he can claim the title of world's greatest assassin. The two both outwit him and survive. Two episodes later, Lupin attempts to steal the sword formula; after being outsmarted, Goemon gets revenge by slicing Lupin's car in half. After both break down into homeric laughter over the situation, Goemon decides to join the gang. The two episodes pull in several elements from the manga stories.
In the 2002 TV special "Episode 0: First Contact", Goemon met Lupin when he was searching for the Zantetsuken, the only sword he felt worthy of his abilities. Lupin, Jigen, and Fujiko all served as adversaries until being forced to work together to survive. There are hints that parts of the story may be made up at the end of the special, however, so not everything can be taken as canon.
Goemon is an incredibly gifted martial artist, both in hand-to-hand and melee combat. However, he is best known and usually employed for his skills in Iaidō and the famous Katana that he uses. His sword goes by the name of Ryusei ("shooting star") in the manga, but it is better known as its animated incarnation, Zantetsuken ("iron-cutting sword").
The katana can cut anything and everything: airplanes, cars, tanks, skyscrapers, and even lightning and a meteorite have been sliced apart by the blade. Its keenness has never been so proven than in the surreal moment when Goemon cut the "film" his animated world was drawn upon, effectively slashing his entire universe in twain. Objects cut by Goemon will fall apart a couple of seconds after he rends them, usually after he has snapped Zantetsuken completely into its sheath. Goemon's speed and skill are such that he can block submachine gun fire with the blade. To Goemon's distaste, most occasions require Zantetsuken to cut unworthy inanimate objects, rather than his using the sword for its designed purpose, namely in battle against a suitably talented opponent.
Zantetsuken has had a number of origin stories over the years, including having been made from the metal of a fallen meteor, or made from a a special alloy passed down through Goemon's clan. In his first TV appearance, the sword is described as being forged from three famous or mystical Japanese swords. A common explanation for its existence is still argued, but its strength and sharpness are constants in everyLupin III incarnation. However, Zantetsuken has also been known to chip or break when applied to a particularly tenacious surface; usually its failure indicates circumstances are the worst possible for Goemon and the rest of Lupin's gang. It is unknown how Goemon has the blade repaired after such damage. It is revealed in The Flying Zantetsuken that the sword has at least one known weakness; it cannot cut a yam based gel named "Devil's Tounge", because it's sticky properties adhere to the weapon.
The second series also gives Zantetsuken a more mystical ability; on a few occasions, the blade acquires a shadow, showing death lurks nearby for Lupin and his gang. Likewise, when the shadow disappears, it shows that the danger has passed. This trait of Zantetsuken appears to be unique to Shin Lupin III, however, and has never been used in any version of Lupin III afterward.
In one episode the sword lost its cutting power, something that happens every 100 years. The only way to return the power to the sword is to make a kind of wedding celebration with the "female" version of Zantetsuken. This "female" sword is smaller than the "male" one, but with the same cutting power. At the end of the ritual celebration, Zantetsuken regained its power. Unfortunately the female sword fell into a pool of magma. It seems that the female sword is lost forever. If it is confirmed, Zantetsuken can maintain its cutting power only for the next 100 years.
Zantetsuken is also the source of Goemon's most famous catchphrase, "Once again I have cut a worthless object," which he says whenever he uses Zantetsuken to do something spectacular that he nonetheless considers mundane (for instance, cutting down a helicopter chasing his friends in Mystery of Mamo). This has been referenced many times in other anime and manga, and has become something of a joke within Lupin itself. In Da Capo of Love: Fujiko's Unlucky Days, Lupin even tells Goemon, "No one is better at cutting worthless objects than you!"
In episode 10 of Steins;Gate, the main character Okabe says (in the dub) about one of his inventions: "Number 5, aka 'I've connected yet another trifling thing,' a la Goemon." This is in reference to Goemon's catch phrase, "I've cut another worthless object."