While easily the least malicious of the many people working for Director Kakuzawa at the Diclonius Research Institute, her impact upon the world of Elfen Lied may be many times worse than those of truly bad intent. At times, she was almost a comedy relief character, but many grim moments and choices awaited her.
A brilliant young scientist, Arakawa nevertheless found herself working as assistant and gofer to the Director's son Professor Kakuzawa after he left the Institute and became an Instructor at Kamakura's 'safety school' university (the rough equivalent of an American Community College). As far as she knew, they were researching a vaccine to prevent an outbreak of children being born with small horns atop their heads and deadly menacing powers. In fact, this was only partly true. The Kakuzawas considered themselves Diclonius (two-horned) as well, and saw the 'Queen' of this new species, a girl they called Lucy, as their ally. Professor Kakuzawa was in fact creating this vaccine as a means of controlling the Diclonius as they emerged as the planet's dominant species, since they expanded by infecting young men to have Diclonius children. With herself doing most of this work and becoming exhausted from it, Arakawa returned one evening to their lab beneath the classroom areas, only to encounter two things that would change her life.
The first one was a young college student named Kouta, searching for his friend Nyu, whom the Professor had tricked him into giving over. The second thing was the shocking sight of the Professor's own severed head, also now bald with his toupee removed, and with the horns she associated with this unknown plague on his head. Urging Kouta to silence, she shooed him away. At this point, neither were aware that the then-infantile Nyu was in fact the gentler alternate personality of the Diclonius Queen Lucy, a vicious killer who had murdered the Professor when he offered alliance with her--though this was after he had attempted to rape Nyu in her sleep.
Contacting the Professor's family, Arakawa was brought by helicopter to the island containing the Diclonius Research Institute, bringing with her the late Professor's head (in a bag in the manga, in a pet transport in the anime). There, she first met the Director. Reasoning out that Lucy must be responsible for his son's death, the Director then demanded to know the identity of the other person to see his son's horns. Arakawa was both reluctant to identify this student and honestly did not really know who Kouta was. Seeing her hesitate, the Director produced a gun and shot Arakawa. Bleeding and believing she was going to die, her life and regrets flashed before her eyes.
In her childhood, her first and best dream was to be a famed scientist on the level of Marie Curie. The position of her family on this dream is unknown, but one manga panel indicates at least indifference. At school, her studious nature caused her to be dismissed by other students and cost her any social life. As she recalls her deep-down for recognition, fame and fortune, she awakens and recalls some limited details about Kouta, pleasing the Director and, coupled with his late son's recommendations, causes him to offer her a job that will give her all she wishes and more. The Director's plan is to replace Humanity with Diclonius, to whom he will be like a new God. To speed this process, he has Arakawa work on weaponizing the virus that is normally only transmitted by the touch of a Diclonius' telekinetic 'arms' called vectors. Finding her old boss's research on a trip back to the mainland, Arakawa then determines to complete his vaccine, thus back-stabbing her new boss and displacing him in the history books by offering Humankind salvation when things seem at their worst.
After the Director's schemes to disperse this weaponized virus began to cause Diclonius' births across Japan and the world, Arakawa then schemed to remove Lucy herself, seeing her as a wild-card who could render her vaccine worthless. Knowing her limitations, she sought only to find Lucy and alert the Director as to her location. But a new obstacle came in the form of a sadistic operative called the Unknown Man by fans, who made a sick wager with her on who could recapture Lucy. Her ego getting the better of her, Arakawa agrees to this wager, but soon realizes she is outmatched. By chance while back at the University, she encounters Kouta in the company of two young women. As he tries to get away, Arakawa seizes one of the ladies as a hostage, demanding he tell what he knows about Lucy, and stating anew how dangerous horned people are. To her absolute horror, she realizes the one she has grabbed and held is in fact Lucy herself, albeit in her Nyu persona. Begging for her life, Arakawa watches the trio flee, realizing she has lost all chance of winning the wager, resigning herself to a grim fate as Unknown Man's sex slave. Undeserved fortune, though, continued to serve her, all in one stroke.
Despite having some very horrible technological edges on his side, The Unknown Man's quest to capture Lucy instead led to his death at her hands, ending the wager for good, much to Arakawa's relief. But her greatest break came when Kouta actually sought her out for information on horned girls. She admonished his naivete and warned him anew, then took advantage of his innocent nature as surely as her former boss once had. Simply following him, she learned where he lived and therefore where Lucy was. Promptly reporting this to Director Kakuzawa, she set in motion a brutal raid upon the main characters' home of Maple House. As she walked away, the first tinges of regret came upon her. These would not be her last.
With Lucy recaptured (or on the verge of being so) and her rival dead, Arakawa returned to the island where the research facility was located. With the Director pleased and very much distracted, Arakawa pursued her own research to its conclusion, devising a full and workable vaccine for the virus that caused men to sire Diclonius children. But literally as she exulted, the facility and the island itself split apart, the result of Lucy's final confrontation with the Director and his family. Arakawa was the only staff member to survive the onslaught of hundreds of deformed clone Diclonii copied from the genes of the late Mariko Kurama, and as she fled, she struggled to protect her vaccine and the accompanying research. She gained two odd allies in this, one, a viable clone of Mariko named Diana rendered obedient by a brain-implant, and a Japanese special agent who used, among other weapons, the customized crossbow of the late unlamented Unknown Man. Though the group made minor headway, after a short time, Diana was killed by her deformed clone 'sisters' and the Agent was out of ammunition for her weapons. The seemingly grimmest turn of all came when Arakawa, hanging on for dear life over a gap in the broken structure, let go of her case containing vaccine samples and research--which, as it turned out, was the very thing the Agent had come to try and find. Reasoning that Arakawa was still valuable as the vaccine's developer, the Agent determined to sacrifice herself (despite appearances, the Agent was a woman) to give Arakawa time to reach her transport and get off the doomed island. While Arakawa bitterly accepted the need for this, she regretted ever more people dying to aid her own life. This also all seemed moot, as Arakawa found the transport chopper in flames, surrounded by clones of murderous intent.
At that moment, an experimental attack craft, ironically powered by organs harvested from these same clone Diclonii, smashed through the column of attackers and saved Arakawa with super-powerful vectors that its operators said exceeded Lucy. Arakawa found this claim laughable, and indeed, the crafts ultimately proved a boondoggle as events escalated. But chastistement by the government operatives running the whole affair plus her own guilt drove Arakawa inward, forcing a hard look at all she had done and the cost the game she had played had levied against the world. At the last moment, an odd movement of clones on the island made Arakawa realize her vaccine had survived, forcing the craft back on the sinking island. With the precious vaccine recovered, Arakawa oddly found herself sad when a look from Lucy confirmed that the Director was dead. As Arakawa watched even Lucy have a last stand that threatened all the world, the feeling of having everything she wanted and yet having it mean nothing at all.
In the manga finale, Kouta relates that Arakawa was indeed revered as a world-wide savior, with wealth, fame and respect, yet every time he saw her on television, she never once looked happy.
In The Anime
Like many character arcs in the Elfen Lied anime, Arakawa's is limited by the short length of its run. Her story is nearly identical to that of the manga, yet at least as presented, she never became a schemer or betrayer. She actually acts to protect Kouta from discovery by the Director at one point. Her more comical aspects, such as not being able to bathe due to her hectic schedule, are emphasized instead. Whether this would have changed in a second set of episodes may never be known.
While anime Arakawa is a typical nervous meganekko, her manga counterpart's fate is somewhat like that of Dragonball's Mister Satan, another revered champion given undue credit. But while Hercule/Satan is fearful of exposure, Arakawa seems in the end to almost wish for it.
Elfen Lied Villains
Lucy \\ Director Kakuzawa \\ Kurama \\ Tomoo \\ Professor Kakuzawa \\ Orphanage Girl \\ Mariko \\ Doctor Nousou \\ Doctor Arakawa \\ Diclonius Research Institute \\ Mayu's Stepfather \\ Mayu's Mother \\ Nozomi's Father \\ Tomoo's Partners \\ Unknown Man \\ Diclonius DNA Voice