Artificial Diclonius
Genetically engineered by Nousou and are all given names by him. Their names are: Diana, Cynthia, Alicia, and Barbara. (Fun to note: the names of the four girls start with the first four letters of the abecedary), twice in the series, Kurama mistakes the clones with Mariko, thinking that she ressurected. They are engineered to have the ability to use their vectors even when in pain and are unable to disobey an order given to them by Nousou. Nousou proves this to Chief Kakuzawa by asking Diana to stab her own heart with a knife, which she does.
After proving their value to Kakuzawa, Nousou is sent with Cynthia, Alicia and Barbara and break in the Kaede hotel with a group of soldiers who attack and restrain the inhabitants, after Kouta is wounded by a shot, Lucy (Now with her horns twice as long as before) kills Cynthia, who was strangling her, she then proceeds to throw a helicopter to Nousou and the two remaining clones, who save him by lifting the flaming helicopter and both of them refuse to leave Nousou despise his pleas to leave him and kill Lucy. After Torturing Alicia by shooting her and dismembering her, Lucy kills her by hurling a garden statue at her head, Barbara escapes death by sliding down the helicopter and opening a hole over Nousou and her head. The next day, she is seen with Nousou in the hospital eating Pocky.
Nousou, wanting to know what where Barbara's real feelings, removes the dispositive on her forehead that controlled her, shortly after, she kills him and escapes the hospital to search The traitor who chose to live among the humans (Nana).
After a short battle, Barbara is killed by Kurama who shot her in point blank at her head.
Diana, still badly wounded, is set free after the black out in the Diclonius facility and saves Arakawa from a diclonius horde mistaking her with Nousou, she gets her device removed from her forehead only to be socketed again.
Part-Diclonius
Chief Kakuzawa (角沢長官 Kakuzawa Chōkan?)
He is the head of the research center at 70+ years old performing experiments on diclonius. He is from a long line of diclonius ancestry that has been watered down by inter-breeding with humans (much of this is, however, only revealed in the manga). As a result of this he has no vectors and much smaller horns on his head, which he hides under a wig. His and his son's aim is, in part, to replenish their bloodline with the diclonius they are experimenting on (of which Lucy is the first to be able to reproduce) and thus gain power as "kings" of the new race, which would wipe out humanity and replace it whole. In the manga, he even claims to desire the position of a god of the new, Diclonius-ruled world he envisions. He is the father of Anna Kakuzawa, professor Kakuzawa and one or more other male offspring.
Voiced by: Kinryu Arimoto (Japanese), Andy McAvin (English)
Professor Kakuzawa (角沢教授 Kakuzawa Kyōju?)
He is the son of Chief Kakuzawa and also a watered-down diclonius with smaller horns and no vectors in his mid-30's. When he and Kurama were younger, they both went to university together and it was Kakuzawa that originally got Kurama involved in the research on Diclonius. He ends up, coincidentally, being the lecturer for a course at the university in which Kohta and Yuka are enrolled. He was the one responsible for releasing Lucy at the research center. He is later beheaded by Lucy after he abducts her and attempts to rape her.
Voiced by: Hiroaki Hirata (Japanese), John Swasey (English)
Minor characters
Kisaragi (如月)
She was Kurama's personal secretary and a graduate of Tokyo University at approximately 21 years of age . She is an outright clumsy but pure hearted woman who seems to space out at work, oblivious to the situation she accidentally stumbles into it. Despite her failures, she is optimistic and has good intentions in doing anything to please Kurama. Her bumbling, airheaded, and innocent demeanor is parallel to that of Mutsumi Otohime of Love Hina. She is killed by Lucy at the start of the story. Kisaragi trips (completely oblivious of what is going on) in front of the rampaging Lucy who takes advantage of her interference to tear off her head and use her body as a shield to fend off the security team's gunfire. In the manga however, Kisaragi came across Lucy while walking down the hall. Noticing that she was covered in blood, Kisaragi approached her. Lucy used this to her advantage and took her hostage. Since Kurama's men were unable to get a clear shot of Lucy, Kurama told Kisaragi they had to sacrifice her. Kisaragi showed no real remorse for this information, saying she was happy to give her life if it meant she was helping. Kurama assured her that her death would not be meaningless, but before Kurama could tell his men to shoot, Lucy tore off Kisaragi's head. After using Kisaragi's decapitated body as a shield and killing the men, Lucy told Kurama that Kisaragi's death was meaningless, and left laughing. Voiced by: Maria Yamamoto (Japanese), Tiffany Grant (English)
Nozomi (ノゾミ)
She is a 15-17 year old soft-spoken and shy friend of Yuka who only appears in the manga from chapter 43 onwards. She has a bladder problem and therefore wears diapers. Kohta first encounters her while walking to the store (not realising they both know Yuka), and both are embarrassed when the wind blows her skirt up. They later meet at the inn and Nozomi is revealed to have a great talent for singing. Nozomi is the person who sings the song "Elfenlied", while teaching Nyū how to sing.
Kohta's Father He was in his mid-thirties when he was killed along with his daughter, Kanae (Kohta's sister), by Lucy as a retaliation against Kohta. In the anime he hears Kohta scream and comes over to see what was wrong where he was swiftly decapitated by Lucy, in the manga he witnesses Kanae's death and goes to attack Lucy in a rage where he is decapitated. Voiced by: Daisuke Ono (Japanese), John Swasey (English)
Tomoo (トモオ)
He was a ten year-old orphan boy living with Lucy and several other parentless children in a child welfare facility. He, along with two other bullies, constantly pick on Lucy every day, primarily because of the latter's physical difference (her horns), though he also adds later on that seems weird for him to see that Lucy never displays emotions. He takes pleasure in making Lucy as miserable as possible with malice by deliberately playing mean pranks on her (like spilling milk on her backpack), calling her "horns" (a pun about her horns), subjecting her to various acts of humiliation, and physically assaulting her. When he finds out that Lucy has been taking care of a puppy, he forces her to witness an act of extreme cruelty by repeatedly smashing a stone (flower vase in the anime) on the dog several times just to watch her cry in order for him to quench his sick curiosity. Instead, a shocked Lucy violently snaps in a murderous rage, beheading him and his accomplices with her vectors.