RahXephon (ラーゼフォン Razefon) is a popular science fiction anime television series about young Ayato Kamina, his ability to control a godlike mecha known as the RahXephon, and his inner journey to find a place with the world around him. The story begins in early 21st century Japan with a seemingly peaceful Tokyo suddenly being attacked by invaders while a mysterious woman stalks Ayato.

Music, time, mystery and personal intrigues are central elements of RahXephon's plot. The series shows clear influences from philosophy, Japanese folklore and western literature, in particular from the writings of James Churchward.

The 26 episode television series was the first directed by Yutaka Izubuchi. It was produced by BONES, aired in Japan January 21–September 10, 2002, and was released on DVD video. The English language translation was produced by ADV Films. The series was aired on television stations in several countries. An alternate movie version was made; many of its scenes are adapted from the TV episodes, but it also features some new scenes. Novels, computer games, an extra OVA episode, an audio drama and several illustration books were also created. There is also a somewhat tweaked manga adaptation.

The premise of RahXephon is the fight between Humans, and pan-dimensional invaders known as the Mulians, short Mu. The Mu appear to be human; the only noticeable physical difference seems to be their blue blood.

In December 2012, two floating cities appear above Tokyo and Sendai. During a conflict with humans that escalates to nuclear war, in 2013, the Mu envelop the entire city of Tokyo and some outlying suburbs within a trans-dimensional sphere resembling Jupiter. The sphere is referred to as "Tokyo Jupiter". This "absolute barrier" is generally considered impassable, although it turns out that with enough power and technology it is possible to cross and even destroy it. The Mu control Tokyo; its citizens are completely cut off from the outside world and have been led to believe that the rest of the Earth has been destroyed. The barrier has a dilatory effect on time, with time inside Tokyo-Jupiter passing about one-sixth as fast as the outside time.

Although RahXephon is usually placed in the mecha genre of anime, its "mechas" are not fully mechanical. The mechas used by the Mu are referred to as Dolems. Dolems are made of clay, like golem, and are animated by a musical force resembling magic. Further, each Dolem is bound to a controlling "instrumentalist" Mulian; when a Dolem is destroyed, the Mulian piloting it is killed as well.

The underlying theme of RahXephon is one of music and sound. A Dolem attacks while singing, and sometimes the attack is the song itself. The RahXephon can also attack by having its pilot — the instrumentalist — sing a song. These songs in turn unleash powerful forces (such as light-energy blasts or heat waves) that cause destruction on an apocalyptic scale. Each of the Mulian Dolems has an Italian name which references musical notation, like "Allegretto", "Falsetto", or "Vivace". The ultimate goal of the RahXephon is to "tune the world". According to the show's creators, the name "RahXephon" is composed of "Rah" (the Mulian sun-god), "X" for the X factor (the unknown), and "-ephon" as a suffix for instrument (-phone).

The unusual relationship between Ayato Kamina and Haruka Shitow is one of the most important plotlines of the series.

Ayato and Haruka first met before the Tokyo Jupiter incident. Haruka lived with her mother, who was a widow at that time; their family name was "Mishima". Ayato, a boy genetically engineered by the Bähbem Foundation to become an instrumentalist, was also living in Tokyo with his adoptive mother, Maya Kamina. His twin brother, Itsuki Kisaragi, was being raised at the Bähbem Manor at the same time.

Haruka and Ayato fell in love with each other and were rarely parted. During the Tokyo Jupiter incident, Haruka Mishima and her mother were away from Tokyo on a holiday trip while Ayato remained inside. Some time after the incident Haruka's mother married again and their family name became Shitow. Haruka's sister, Megumi, was born. In the meantime, Haruka had a short relationship with Itsuki Kisaragi, perhaps because of his physical similarity to Ayato, and she began wearing her hair shorter.

Ayato sustained heavy mental damage from losing his beloved one, and Maya modified his memories to make him forget Haruka. There is considerable evidence scattered throughout the series that the entire population of Tokyo Jupiter has also been collectively brainwashed by the Mu. Though Ayato had forgotten Haruka, visions of her continue to haunt him, as manifested in his art. Ixtli, RahXephon's soul, also adopted Haruka's appearance and family name (Mishima) but took a different given name, Reika.

By the time Haruka infiltrates Tokyo Jupiter and meets Ayato again, time dilation has made her and Itsuki considerably older than Ayato. Despite his original mistrust, Ayato gradually re-discovers his love for Haruka.

At the end of the series, Ayato ascends to the status of a new god (together with his genetic mother, Quon Kisaragi). Haruka flies to be with Ayato, or perhaps to wake him from his fury, but the RahXephon's energy beams, aimed at Quon, destroy Haruka's fighter jet instead. After Ayato's RahXephon defeats and merges with Quon's, he "re-tunes the world" (i.e. modifies the past) so that he and Haruka would not have been separated. In the final shots of the series, adult Ayato (who can now easily be mistaken for Dr. Kisaragi) is seen with Haruka and their daughter, named Quon.

From Wikipedia