Iwakura Lain The title character. Lain is a somewhat laconic, attention-wavering junior high-school girl that at first seems not to have much interest in anything. When she begins to explore the Wired with her Navi, her aspect begins to change into that of a much more social nature.

Iwakura Kou Lain's father. Kou is a computer hardware fanatic and spends much of his time tinkering with his system setup and the Wired, almost to the exclusion of all else. He is interested in his daughter's growing fascination in the Wired, but begins to have unsettling doubts about the whole affair as the Lain delves deeper.

Iwakura Miho Lain's mother. Like her father, Lain's mother seems distracted from the family clique more than would appear healthy. She does spend time with her husband and dutifully prepares the family meals, but at times it appears as if she regards Lain as a stranger.

Iwakura Mika Lain's older sister. Mika is at first the typical somewhat rebellious, "late-nights-out" high school girl, but as Lain becomes more outgoing, Mika seems to regress into a solitary type.

Kato Juri One of Lain's friends, a timid sort of girl. She is reduced to tears when the email from the dead Chisa arrives in her inbox.

Mizushiro Alice Lain's best Friend. Alice is a kind girl who manages to interest Lain in such things as e-mail and going out to a dance club. The only one who truly regards Lain as a friend.

Yamamoto Reika The 4th member of the girlfriends group (Lain/Alice/Juri/Reika). Reika is the haughtiest of the girls.

Yomoda Chisa A girl in the same grade as Lain; she commits suicide in the opening act, but speaks to Lain from out of the Wired nonetheless.

DJ The manager of the Cyberia nightclub. Cyberia is noted for being a black-market for designer drugs such as "Accela", which appears to be more like "Tek" (as in William Shatner's 'Tekwar' series) than a chemical drug. Another interesting piece of tek is "Psyche", a non-sanctioned upgrade for Navi consoles.

The Knights A small group of "elite operators" in the Wired. Their corporeal world selves are rather normal. They can manipulate things to a dangerous degree online, however.

Men in Black - The "Agents" These are men sent from the Tachibana Laboratory, the company that wrote the core of Protocol 6. The company knows something is amiss with Protocol 6, and for some reason these field agents begin to follow Lain.

Taro, Myu-Myu and Masayuki A group of hacker kids, often seen at Cyberia even though they are not older than 12. Taro is especially knowledgeable about the more avant-garde aspects of the Wired, and at times could be considered a 4th in the Knights. His tool of choice is a toy gun that converts into a wireless PDA-Navi.

Professor Hodgson The now-invalid lead scientist on the KIDS project from some 15 years back. Hodgson notes that the data on the KIDS project--thought deleted or destroyed--has begun to appear in use on the Wired.

Masami Eiri A programmer at Tachibana Labs, it was he who wrote encephalic algorithms based on the fundamental vibrations of the Earth into Protocol 6. He is known by quite a different name in the Wired.