Yakumo Fujii, the son of an archeologist, is working at a restaurant one day when a strange Chinese girl named Pai enters and asks Yakumo to help her become human. For Pai is the last of a race of three-eyed immortals known as a Sanjiyan Unkara, and after granting Yakumo immortality, he is now charged with protecting her. However, doing so won't be easy; even though Yakumo is now immortal, he still only has the powers of a normal human being. With few clues to follow and plenty of stronger beings on the hunt for Pai's life, will Yakumo succeed at helping Pai become mortal?
In the near future, some girls are born mutated. Known as Diclonius, this new species is believed to have been chosen by God to wipe out mankind. Unlike regular humans, Diclonius have two horns on their head and ‘vectors' - invisible ‘hands.' Contained within a research facility unknown to the world, the Diclonius are experimented upon mercilessly; many die or develop a hate for mankind. One such creature, Lucy, is said to be the first of the Diclonius. She escapes from the facility, but while fleeing she takes a bullet to the head and is seemingly killed. However, it seems Lucy isn't quite dead yet; she's instead developed an alternate personality called Nyuu. She's washed up on a shore where two people, Kouta and Yuka, find her and bring her home, unaware that such a monster still lurks within Nyuu.
The main female character in both Elfin Lied and 3x3 Eyes have very strong forceful personalities, not to mention the fact that neither one of them is human! There are some awkward developments with the hero of the story because the personality of the heroines changes from nice to an entirely different character altogether, one that is stern and even antagonizing. The charm of the innocent girl verses the serial killer aspect in both Pai (3x3 Eyes) and Nyu (Elfin Lied) is very intriguing.
Yuusuke is a street-fighting, class-skipping juvenile delinquent. Killed in an unexpected act of kindness, he thwarts the spirit-world bureaucracy and ends up with a second chance at life... as infant prince of death Koenma's Spirit Detective! Simultaneously cheered on and kept in line by Keiko Yukimura, his childhood friend, he is joined by a spiritually aware human, two demons on parole, and guided by a much too lively ferry girl of the dead. Together they plow through demons, tournaments, hijinks, intense "martial arts" training, cross-dressers, dungeons, conspiracies and bad puns alike. At the end of the day, what's it all for? Kicking butt and saving the world, of course!
The feel of Yu Yu Hakaso and 3x3 Eyes are very similar in style with a great deal of fighting and manipulation of the characters overall attitude towards how they lead their lives. The heroes have to struggle with the dilemma of what they are fighting for and develop some supernatural powers along the way.