Tachikoma

A Tachikoma (タチコマ) is a fictional AI walker/roller in the Ghost in the Shell universe, appearing in the manga created by Masamune Shirow and the Ghost in the Shell: Stand Alone Complex sub-universe. Nine of them are assigned to Section 9's use originally. They are best described as a "spider type multi leg combat vehicle equipped with artificial intelligence". The spider design appears in other places in Shirow's work, like the Appleseed manga. Shirow is noted to keep numerous spiders as pets.

Production IG was unable to use the Fuchikoma design in the 2002 Ghost in the Shell: Stand Alone Complex TV anime series due to copyright conflicts. However, Masamune Shirow was able to design a legally safe equivalent to the spider-tanks for the new show, which he named the Tachikoma. There are distinct differences in the design, most significantly in the 'eyes' and the vertically-oriented abdomen. Still, the tanks are easily recognizable as descendants of the original Fuchikoma. Their AI 'personalities' and roles in the new series are indistinguishable from their predecessors in the manga.

Design
Tachikoma are as large as an average sedan, are painted blue and have four "eyes" fitted on the surface of their bodies. Three are on the "head" and one is beneath the abdomen. Each eye has three pinholes, loosely resembling a bowling ball. These eyes sometimes become expressive in the typical anime style. Tachikoma are controlled by individual AIs, are capable of speech and generally exhibit a childish, curious, joyful and active personality, although they are consummate professionals in the field. They normally operate as independent units and receive orders from human agents, but they can also be directly piloted from a cockpit in their abdomen. Its design is implicitly based on that of the jumping spider in terms of bio-mechanical modelling, and system technical design was based on the Fuchikoma.

Tachikoma have four legs and two arms. They can move by walking, or they can drive at high speed by using the wheeled footpads on each of their four legs. Each wheel appears to be angled and omnidirectional, allowing the Tachikomas to move in any direction with their drive system, which can control all degrees of freedom in its task space. Other abilities of the Tachikoma include jumping great distances, sticking to vertical or inverted surfaces, engaging a thermoptic camouflage mechanism, and grappling/rappelling using their adhesive string launchers. Tachikoma maintain control of their legs while using wheels to drive down a road, and shift their weight around turns. They can also roll briefly on to two legs while driving to avoid an obstacle or pass through a narrow space. To make balance easier, they can move their heavy abdomens with a Ball joint.

Standard Tachikoma equipment includes a 7.62x51mm light machine gun mounted in the right arm, a secondary weapon hardpoint in the "snout" (usually a 50 mm grenade launcher, capable of launching both explosive and gas grenades, but which can be replaced by a six-barrelled 12.7x99mm Gatling gun), a universal cybernetic connector on an extensible, prehensile cable in the left arm, liquid wires that can be used for grappling, rappelling or for restraining purposes and a built-in thermoptic camouflage system.

AI
Though they possess individual artificial intelligence, every night they are synchronised, so they start the next day with identical consciousnesses that are each the sum of their total collective experience and development. This leads to identity confusion, since each Tachikoma has the same memories.

A notable paradox arises from this synchronization, however. Though the Tachikoma have identical memories, their personalities and opinions are distinct. During the Stand Alone Complex series, an episode is entirely devoted to discussions among them.

It is explained in the last episode of the first season that it is their curiosity that lets them be different from each other. It is curiosity that saves a personality from dying when linked with others.

These separate personalities reveal three 'main' Tachikoma. The first one considers itself Batou's personal Tachikoma, which has a personality of a hyperactive child. It is curious, inquisitive, and tends to get many 'bright' ideas. It is special, given that Batou pampers it with natural oil and refuses to operate any other while on assignments. The second major Tachikoma (possibly favored by Major Kusanagi) is more logical, acting as the straight man to the first. The third Tachikoma appears somewhat slower than the others, and at times has difficulty keeping up with the other Tachikomas when discussing such in-depth topics as what it means to be "alive". There is also a fourth Tachikoma with a distinctive personality, who is a bookworm and an intellectual. Its body was taken apart during the experimentation incident, but its AI has presumably been saved for further analysis.

At one point in the series, while all but three of the Tachikomas are either locked away in a lab for study or dismantled for study, three surviving Tachikoma units abandon their civilian posts to assist the Major and Batou. This is the only time in the series where the Tachikoma vary in appearance, as a few units have been disarmed for either study or to be sold off to civilian contracts. Batou's unit remained unchanged, although it was given a set of decals to represent its new ownership. The other two have been more extensively repainted and or modified, with the remaining laboratory unit's cockpit having been replaced by a much smaller diagnostic module, and the other contracted unit now bearing a construction color scheme.

Stand Alone Complex
In episode 12 of the Ghost in the Shell: Stand Alone Complex, one slightly-malfunctioning Tachikoma goes on a joy-ride through the city where it meets a young girl named Miki who is looking for a lost dog. The episode is mostly comedy but turns serious, with the Tachikoma attempting to understand sadness and death. In a later episode, the Tachikomas argue among themselves over which met Miki, since they all have the same memory. Yet when Batou calls for his Tachikoma only his actual Tachikoma raised its hand. As it leaves with Batou, it suddenly remarks with quiet surprise that it indeed must have been the one that met Miki.

Batou has the most affection for the tanks, picking out one tank as "his" and spoiling it with natural oil instead of synthetic. This is what causes his to go haywire later, when the natural oil dissolves some of the proteins in the Tachikoma's AI neurochip. On the other hand, Togusa, the least cyberized of the Section 9 staff, holds a less idealist view: "they're just machines." Aside from leading to an indignant outburst from the Tachikomas (who accuse Togusa of bigotry), it sets up something of an antagonistic relationship between Togusa and the tanks, which is revisited in an episode in season two. Major Motoko Kusanagi holds the most pragmatic view of all. Her only regret following the Tachikomas' suicide attack is that she didn't get a chance to dive their AI, and discover whether or not what they had acquired was really a "ghost". In the manga, she expresses concern over the evolution of the Tachikomas' AI and orders it monitored to catch any undesired emotional developments or an unwanted "rise of the robots."

The Tachikomas also show a slightly mischievous side in episode 15, "Time of the Machines". They confuse a Section 9 operator with the same self-referential logical paradox which featured in the Star Trek episode, I, Mudd, wherein Kirk and Spock confuse an android with a statement along the lines of "Everything I say is a lie, and I am lying." The Tachikomas likewise use the Epimenides paradox to get the admin drone stuck in a logic loop. Interestingly, not only is the Tachikoma unaffected by the statement, the drone is unaffected until the Tachikoma explain why the statement is a paradox. They then steal a piece of equipment left in the drone's care and ridicule it for being fooled.

By the end of the series, the Tachikoma fleet start approaching sapience; all are sent back to the lab for dissection, amidst fears that they are no longer fit for combat duty. It is the use of natural oil in Batou's personal Tachikoma (all other units used synthetic lubricant) that acted as a catalyst for the behavioral anomalies that began to manifest as sapience. Major Kusanagi subsequently bans the use of natural oil prior to the later decision to halt deployment of Tachikomas in field ops.

Three Tachikoma survive the lab analysis, (one blue, calling itself "Batou's Personal Tachikoma", and two others, repainted yellow and silver) and prove their worth when they abandon their new civilian jobs to save their imperiled comrades, without explicit orders to do so. The silver Tachikoma is destroyed on sight when it finds Batou under attack by an Armed Suit, a bipedal power-actuated armored exoskeleton. The blue and yellow Tachikoma combine their efforts to save him, and conduct a desperate and ultimately suicidal attack against the Umibozu, while Batou watches from a nearby terrace with a stricken look on his face. This selfless act is the last thing they ever do. Because of their devotion, the collective Tachikoma consciousness is restored from the backups made during the dissection process and loaded into a new fleet, which appears in the second season.

S.A.C. 2nd GIG
In the second season, S.A.C. 2nd GIG, the enforced synchronizations among Tachikomas are halted, since Motoko Kusanagi allows them to preserve their own personality after acquiring sapience in the first season. They can still share information and sensation with synchronization if they want to, and also specify which area to share. The Tachikomas are also outfitted to perform complex networking tasks including netdiving, to aid Section 9. Several episodes featured the Tachikomas operating in the nets using a representational avatar, instead of their map symbol of a triangle in a circle. They navigate the net as though flying through it. The final episode indicated that while operating within the net, they could not inhabit their physical units.

It is hinted that Tachikoma units developed ghosts. During the finale of 2nd GIG, while ordered to create a repository in cyberspace for the memories (and hopefully, ghosts) of all refugees of Dejima, they secured instead their own memories within the netspace and selflessly sacrificed their AI satellite to prevent a nuclear explosion. A fellow AI, the bioroid Proto, knows what is happening and says he would swear they had ghosts right before the satellite and missile made impact.

The destruction of their satellite appeared to result in the Tachikomas' AIs being obliterated. This seems to be confirmed in the final moments of 2nd Gig, where the members of Section 9 are seen using a replacement, the Uchikoma. However, during another scene in the finale, one Tachikoma can be seen placing a globe with the label TACHIKOMA'S ALL MEMORY in a large memory storage unit in cyberspace.

As a side note, during the Tachikomatic Days short for the final episode, one Tachikoma, presumably Batou's from its behavior, found itself alone in a white area which did not appear to be what they viewed as the afterlife. While fully colored and shaded, it encountered a blank line Uchikoma in a shower of sakura petals. This may indicate a planned merging of the two AIs in the future or the evolution of the Uchikomas.

Uchikoma
The think-tanks seen in the last episode of 2nd GIG are named Uchikomas (ウチコマ), similar to the Fuchikoma think-tanks used in the original Ghost In The Shell manga. In design terms too, they represent a fusion of the design features of the Tachikoma as seen in the series and those of the Fuchikoma, with "faces" and "abdomens" similar to the Fuchikoma and legs and "thorax" more akin to those on a Tachikoma.

Solid State Society
During the early portion of the film, the Uchikomas are seen being used by Section 9 in a way similar to the way the un-evolved Tachikomas had been used. In fact, they were so unevolved that one used incorrect tactics during a mission and the tank's training program had to be redone. However, the reappearance of the Major also brings the reappearance of the Tachikomas. Initially they are seen in their new cyberspace form, sporting different colours and even racing stripes and individual names (implying unprecedented allowance for individuality from the Major) that include Max, Musashi, Loki, and Conan. They eventually are reunited with their physical bodies, and rejoin Section 9 as full members along with Major Kusanagi.

Tachikomatic Days
Tachikomatic Days (タチコマな日々, Tachikoma na Hibi; also known as Tachikoma Specials or Tachikoma Days) are a series of comedic shorts attached to the end of every episode of Ghost in the Shell: Stand Alone Complex. The shorts takes up a little over a minute and features the antics of the Tachikoma think tanks of Section 9 and usually involves plot points from the episode it accompanies. Ghost in the Shell: S.A.C. 2nd GIG (the second season of the TV series) also has Tachikomatic Days at the end of each episode. Tachikoma Days are also attached to the end of each episode on most of the DVD and iTunes releases of both series.

Tachikomatic Days is not aired on Cartoon Network's Adult Swim broadcast of Stand Alone Complex and 2nd GIG. However, they are shown on Adult Swim's free webcast programming service Adult Swim Video. On Australia's Cartoon Network's Adult Swim, the Tachikomatic Days shorts are broadcast with each episode. The UK's AnimeCentral broadcasts Tachikoma Days with each episode.

Voice talent
In the Original version, all the voices were done in monologue style by seiyū Sakiko Tamagawa.

The voices of the Tachikomas in the American dub are provided by a number of well-known voice actresses who specialize in high-pitched, child-like voices. Among them:


 * Melissa Fahn, best known for voicing Ed in Cowboy Bebop, Rika in Digimon Tamers, and Gaz in Invader Zim.
 * Rebecca Forstadt, (aka Reba West), best-known for Lynn Minmei in Robotech and Sugar in Little Snow Fairy Sugar - This is Batou's Tachikoma.
 * Lara Jill Miller, who voices Clifford the puppy on Clifford's Puppy Days, Kari Kamiya in Digimon Adventure/Digimon Adventure 02 and Juniper Lee in The Life and Times of Juniper Lee - This Tachikoma is the "brains" of the group.
 * Sandy Fox, who has provided voices for numerous anime and western cartoons, including The Simpsons, The Critic, Steven Spielberg's Toonsylvania, Please Teacher!, the .hack franchise and Chobits.
 * Sherry Lynn, best known for voicing Sasami in Tenchi Muyo! - This Tachikoma is usually the one that assists Kusanagi on missions.
 * Julie Maddalena, best known for voicing Sarah McDougal in Love Hina.
 * Peggy O'Neal, best known for voicing Suzie Wong in Digimon Tamers and Yakumo Tatsuro in Shinzo.
 * Lia Sargent, best known for voicing Milly Thompson from the anime Trigun, as well as the longest serving actress for Chun Li in the adaptations of Street Fighter II: The Animated Movie, Street Fighter II V, and Street Fighter Alpha.
 * Michelle Ruff, best known for Rukia Kuchiki in Bleach, Chi in Chobits and Yuki Nagato in The Melancholy of Haruhi Suzumiya.