Lucy is a teenage diclonius girl, around 18 years old and the central protagonist/antagonist of the series. Lucy has four vectors with a limited range of about two meters. However, she can be swift and lethal within that range, and will use any nearby objects as high velocity projectiles to kill at greater distances. She is also capable of stopping or deflecting most standard ammunition when she concentrates on the task.
Lucy hates humans mainly because of how she was treated by her human peers as a child, of whom she eventually killed several after they captured a puppy Lucy had been caring for and beat it to death in front of her. Consequently, she discounts non-diclonii, claiming they are not real people, to the point of telling Nana that she has "not killed anyone yet". She seems to lack empathy and kills without much concern and normally as a first reaction. She is incredibly sadistic, amputating limbs and blinding foes, leaving them to bleed to death rather than killing them outright. Despite this lack of concern for human life she will not harm Kohta, and cries and apologizes for killing his family in a fit of jealousy; she loves Kohta, but due to her vengeful nature, she believes he will be content without her existence. As such, she refrains from killing in his presence, except in the anime, when at the end, she kills a whole army in front of him. However, Lucy still isn't above acts of jealously, once using her vectors to shove Yuka when she saw her holding hands with Kouta. She never refers to herself as Lucy, but thinks of herself as "Kaede", which is the name she uses to sign her letter to Kohta in the manga. After her death in the manga, Kohta and his daughter are approached by two twin girls with ribbons in their hair, heavily implied to have some connection to Lucy.
