The name "Chobits" comes from the fact that her creator, Ichiro Mihara, used the word "Chobi" to describe anything he thought was "small and hopelessly adorable". Two Chobi (Chi and her sister Freya) become "Chobits"
She is found by Hideki one night in a pile of trash as he makes his way home from work. He takes her to his apartment and tries to figure out how to activate her. A typical persocom (abbreviated from "personal computer") has its power switch in or behind its ears, but Chi's is located in a very unorthodox place: her vagina. Realizing this, Hideki overcomes his moral objections and manages to activate her. She has difficulty communicating with him at first; the only word that she is able to say being "chi". She is initially fearful that Hideki will discard her because of this, but he reassures her that he would never throw her away. When Hideki decides to give her a name, he remembers the only word that she can say and decides to call her "Chi".
Chi remembers nothing of her past life and is unable to perform simple tasks, so Hideki takes it upon himself to teach her and take care of her. Mimicking Hideki and several other outside influences, Chi proceeds to start learning about the environment around her. She makes many humorous mistakes in the process, including her imitation of a pornographic pose from one of Hideki's magazines, and calling everyone and everything "Hideki".  Role in the series  Type of persocom
Hideki tells Shinbo about finding Chi, and asks for his help in setting her up. Shinbo connects Chi to the television, but the only information displayed is "No Data". He muses that it must mean that Chi's data has been lost, or that none has been installed yet, although he is confused on how she can be mobile if there is no operating system installed. He suggests that they use Sumomo to analyze her to discover what company made her and what model she is. Unfortunately, Sumomo's system crashes when she is connected. Under the impression that Chi is a custom-made persocom, Shinbo suggests that Hideki take her to Minoru, a persocom expert.
Minoru is curious about Chi's abilities, and he agrees to scan her; four of his custom models are used, each one crashing during the attempt. While this astounds Hideki, it only heightens Minoru's curiosity. Another one of his persocoms, Yuzuki, suggests that she try scanning Chi. Minoru reluctantly agrees, and Yuzuki connects herself to Chi. Her attempt also fails, although she is able to disengage with a minimal loss of data. Amazed by Chi's ability to repel Yuzuki's probe, Minoru begins to suspect that she may be a Chobit; a legendary persocom rumored to possess true sapience. He suggests that he post about her on a persocom forum that he frequents to see if anybody online has any idea what make she is. He later receives a strange image via email from an untraceable sender; the image depicts a persocom identical in appearance to Chi except for the word "HOBIT" on one leg. Hideki shows the image to Chi, but she claims that this is not the same persocom as herself. Minoru is later sent a second image from the same anonymous user. This image depicts the same persocom with two scientists, one of whom is Chitose Hibiya.  Employment
At one point Hideki considers having to take on a second job due to his poor financial state. Chi, looking through one of his magazines, sees a job advertisement and shows it to Hideki with the suggestion that she take the job, completely unaware that the advertised position is for a dominatrix. Hideki is both embarrassed and furious, and an upset Chi asks why she cannot have a job. Hideki hastens to reassure her that she can have a job, but it's just the type of job that matters. He tells her that when he gets home from work he'll talk to her about getting a good job. Chi accidentally in Yumi's uniform at Chiroru bakery.
Chi disregards this and leaves the apartment shortly after Hideki, looking for a job. She is soon approached by a stranger, who asks her where she is going. Upon learning that she is searching for a job, the man invites her to follow him, saying that he has been looking for a girl to work for him. Chi asks if it is a "good job", and the man answers yes, saying that it has short hours and lots of pay. The job in question is that of a stripper at a peep show. Minoru and Yuzuki, searching online for any possible information pertaining to Chi's past life, stumble across live video of her at the peep show as she waits for instructions on what to do. Minoru contacts Shinbo through Sumomo, and a nearby Hideki overhears their conversation. He takes Sumomo and she directs him to the location of the peep show.
The owner of the peep show tries to direct Chi on how to put on a good show for the customers. Chi is unable to take off her bra, so the man tells her to take off her underpants and put her fingers into her vagina. Chi is about to do so when Freya intervenes and warns her to stop. Perplexed and under the assumption that Chi is running some sort of program, the owner attempts to show her how to do it. Chi resists, destroying the room in the process and escaping outside just as Hideki arrives.
After Hideki manages to find Chi and bring her home, he reassures her that she did not do anything wrong, and that if she truly desires a job, he will help her to find a good one. He is eventually able to this, convincing Hiroyasu Ueda to employ her at his bakery during his anniversary sale. Ueda is very impressed with her effort, stating that she made no mistakes and worked diligently all day. He asks her if she would like to work there full time and a delighted Chi asks Hideki for his permission to do so when she arrives home from work.  Kidnap
On one occasion Hideki is unable to walk Chi to the bakery, so she is forced to make the trip alone. While standing outside a bookstore examining the latest copy of A City with No People, she is kidnapped by Yoshiyuki Kojima, who recognized her as being the strange persocom Minoru had posted about. Under the assumption that she must be an especially powerful persocom to have captured the interest of Minoru, he comes to believe that she might be a Chobit. Yoshiyuki connects her to all of his custom-made persocoms (the only exception being Kotoko), and initiates a program that he had created especially for Chi that is designed to break through her firewalls. Chi restrains Yoshiyuki Kojima during her kidnap.
After Hideki is told by Ueda that Chi hasn't shown up for work, he begins to suspect that she may have been kidnapped. He contacts Minoru and begins to search the streets for her. At the same time, Minoru is systematically searching through the IP addresses of every member of the persocom forum to try and determine who had sent the strange images before. He is then sent another image, this time a street map. He contacts Hideki, who is searching for Chi with Shinbo and Sumomo. They run through all of the IP addresses registered on the forum and narrow the possible locations of the kidnapper down to a nearby area of Tokyo. Minoru checks to see who the IP address is registered to and realizes that it is Yoshiyuki, who goes under the alias "Dragonfly". He tracks Sumomo and superimposes her location onto his map, and when they arrive on the street they are able to determine which house Chi must be in.
Yoshiyuki is amazed that Chi has been able to block his program after an hour of continuous running, but he is confident that it will not take much longer to break through her defenses. He hugs her in delight at how powerful she is, and then begins to grope at her. Freya intervenes again, binding Yoshiyuki with all of the wires connected to Chi, and then releasing a powerful concussive blast. At this moment Hideki and Shinbo appear and Freya vanishes, causing Chi to collapse. She recovers and briefly reunites with Hideki before losing consciousness. Shinbo then forces Yoshiyuki to transfer Kotoko's registration to Hideki in order to prevent Yoshiyuki from deleting her memories, so that a record of his attempted kidnap exists. The next day, Hideki and Chi then leave to find Ueda and let him know that Chi is safe.  The Person Just for Me  In the anime
An organization known only as "The Syndicate" is aware of Chi and her special programming. Under the impression that something terrible will happen if her program executes successfully, they send two persocoms, Zima and Dita, to destroy her. They have been created from the same system architecture as Chi, and are immune to her ability to freeze other persocoms. However, Zima wants Chi to succeed in her task, and purposefully misinforms Dita of Chi's whereabouts. Chi's program is almost completed when Zima unwillingly gives away her position to Dita, who goes to destroy her.
Hideki arrives and goes up to his apartment room. Once inside Chi tells him of her love, asking if it is requited. Hideki responds in the affirmative, and they embrace briefly before Chi's program executes. Chi floats up to the roof of the apartment and begins to run her program, freezing every persocom with the exceptions of Zima and Dita. Dita attempts to hack into Chi, who repulses it easily. Dita then connects directly and begins to shut Chi down. Hideki makes his way on to the roof to save Chi, but he is restrained by Zima. Dita explains to him that for the good of all persocoms, Chi must be destroyed. After hearing Hideki's pleas, Zima releases him and grabs Dita, disconnecting her from Chi. With the connection broken, Chi is able to complete her program but chooses not to. She retreats inside herself, and Freya takes control as Chitose Hibiya arrives on the rooftop.
Freya explains how she came to inhabit Chi's body. She reveals that Chi and herself merely switched places inside the body, but Chi has shut herself away and Freya cannot contact her. Hideki asks why and Freya explains that Chi discovered there were certain things that humans could do but she could not, leading her to believe that while Hideki would love her, it would make her existence unbearable. Hideki protests that it would not, but Freya tells him that Chi thought otherwise. She then tells Chitose that the time has come to destroy both of them, and she reluctantly agrees. Against Hideki's protestations, she deactivates Freya.
Disappointed by the outcome, Zima leaves with Dita. Chi, however, has survived the deactivation and come to the conclusion that while life with Hideki may seem painful because of her limitations, it is even more painful without him. She regains control of her body and completes her program, giving every persocom the ability to love.  In the manga
The events in the manga proceed quite differently from the events in the anime. In the manga, Zima and Dita are agents not of The Syndicate, but rather the Japanese government, who know that the activation of Chi's program will result in the deletion of the person-recognition programs of every persocom in the world. As in the anime, Zima declines to inform Dita of Chi's location or level of program completion until Dita forcibly reads it from him. After Zima and Dita arrive at Hideki's apartment, a minor scuffle ensues between Dita and Chi, before Zima restrains Dita from attacking, wishing to see the outcome of Hideki's decision. Hideki confirms his love for Chi, only to find that Freya has taken control of Chi's body. Freya then explains to Hideki that he can never engage in sexual intercourse with Chi without formatting her systems, erasing everything that makes her a unique individual. Hideki states that he will love Chi regardless of this fact.
Freya then confirms that Chi and herself are indeed the legendary Chobits, but unlike the Chobits of legend, they are not truly sentient, nor do they possess emotions, but rather, they rely on the execution of software routines just like every other persocom. Even knowing this, Hideki says that he will still love Chi. Before relinquishing control of Chi's body, Freya asks Hideki if he would like to know what Chi's special ability is. Hideki declines the offer, and after imploring Hideki to take care of her sister, Freya vanishes and Chi awakens, embracing Hideki.  Limitations
Despite her nature as a highly advanced persocom, there are still things that Chi cannot do. These range from simple set backs such as the inability to produce offspring, to the more deleterious inability to have sexual intercourse. This is because the location of her power switch is in her vagina. Because of this, even if Chi is in love with Hideki she cannot have a sexual relationship with him since that will cause her to restart, reformat, and lose all of her memories with him. However, Hideki says that this will not stop him from loving Chi.
In the anime it is possible this may not be the case. In episode seven during Chi's time at the peep show, it is stated by Freya that "regardless of what happens, until someone who truly loves you appears, never let anyone touch you here." It is notable that this warning is also said in the manga. This warning is repeated in episode twenty-two when Yoshiyuki (Dragonfly) tries to take advantage of Chi. Just as before, a defense mechanism is activated and Yoshiyuki is subdued. Chi then states that since he isn't the one for her, he isn't allowed to come inside. Finally when Hideki arrives on the scene, Chi explains that only the one for her is ever allowed to come inside, and teaches him what she means by using his hand.  Relationship with other persocoms
As a Chobit, Chi possesses many abilities that affect her relations with other persocoms. She is designed so that she has the ability to read data from other persocoms without opening a direct connection to them. She also possesses an extremely powerful firewall. When Shinbo attempts to use Sumomo to scan Chi and find out what programs have been installed, Chi's firewall causes Sumomo to crash; an action later repeated when Yuzuki attempts to scan her. Even when Yoshiyuki connects all of his most powerful persocoms into a large parallel processing network, they are not able to penetrate her defenses. In addition, Chi also has the ability to freeze other persocoms and enable them to hear a "familiar voice."  Elda
Before she was found by Hideki and named Chi, her name was Elda. She was the second Chobit produced by Ichiro Mihara. Elda was created after Mihara's wife, Chitose Hibiya, noticed that Freya, the first Chobit, was becoming increasingly depressed as time went by. Elda was created to be Freya's little sister, in an effort to make her happy. In spite of this, Freya's condition continued to worsen, eventually forcing Elda to take Freya's mind and memories into herself in order to save her. In the manga, Elda loses her own memories as a consequence of this act. In the anime, it is explained that Hibiya reset Elda's memories after her husband's death. Also in the manga, after Elda took on Freya's heart, her last request before losing consciousness was to be left alone outside, away from her family, so that there would be no possibility the same fate that befell her sister could befall her.
Before doing this, her father gave her a "gift"; this gift was a program, designed to do one thing. If in her new life, Chi failed to find the Person Just for Her, she would connect to every persocom on the planet and execute a program that would delete the individual-recognition abilities of all persocoms, so that they would never be able to distinguish one person from another ever again. If Chi failed to find the Person just for Her, it stood to reason that other persocoms would suffer the same fate as well. The purpose of this program was to spare the persocoms of the world the pain of unrequited love. In the anime, this program appears to have an alternate effect; if Chi finds the Person just for her, all persocoms would be granted the ability to feel emotion. The reason for this is since Ichiro Mihara was the creator of persocoms, he viewed them all as his children. His wish was that if Chi were able to find someone who loved her in return, all his children would be able to share in this happiness by being able to feel emotions the way humans do.
After Mihara's death and Elda's reset, Chitose creates the children's book series A City with No People, a story within a story. It is about the interactions between people and persocoms (referred to as "it" or "them"), and the journey of the narrator and her mirror image as they attempt to find "the person just for me." The publication of this series is a way that Chitose can help Chi's program to execute, which remained intact after the reset. Hideki buys the first volume for Chi, and as the series progresses she obtains all of the sequels.
"Elda" is the official English spelling of her name, although "Erda" would have made more sense as a direct translation. The name is written in Japanese as "エルダ" (Eruda) which is also used to write the name of the Norse earth goddess Erda (or Jord), the mother of the Valkyries. The word "Jord" also means Earth in Norwegian, Danish and Swedish.