These profiles contain minor spoilers for this series. If you don't want to know who some people are, then just go back.
Lain Iwakura
A shy, isolated, 13 year old girl. She is in 8th grade and is the main character of the show. She gets involved in the Wired and her life becomes very complicated. As she visits the Wired more often she develops a "Wired personality", (serious with a bad attitude) which she only has while connected to the Wired. While out in her "normal" life she is just quiet and shy. She doesn't know who she is or where she came from, but she is very powerful in the Wired.
Yasuo Iwakura
Lain's dad who encourages her to get involved in the Wired and make friends there. He later becomes concerned because of Lain's time spent with her Navi. He really does care for Lain.
Miho Iwakura
Lain's mom. She doesn't pay much attention to Lain or Mika. She often just makes dull comments and doesn't like talking to her daughters. She is only nice to Yasuo.
Mika Iwakura
Lain's older sister. She thinks Lain is weird. Mika is a pretty spacey person, really mellow. Later in the series she goes crazy, most likely affects of the Wired. She just sits around and mumbles gibberish.
Arisu Mizuki/Alice
Lain's best friend. Arisu is always sticking up for Lain and she tries to bring her along with Juri and Reika to have fun. Arisu really cares about Lain. She tries to bring out the fun part in Lain. She is always kind to her and becomes concerned when Lain changes once involved with the Wired.
Reika Yamamoto
She is one of Arisu's friends. She teases Lain a lot and doesn't seem to like her much. She's more serious than Juri and sometimes more rude.
Juri Kato/Julie
Another of Arisu's friends. She also teases Lain, but can be nice to her when she wants. She is sometimes insensitive to other's feelings.
Chisa Yomoda
She is a girl who committed suicide at the beginning of the series. She sends Lain, Juri, and other kids, e-mail about the Wired after her death.
Taro, Myu-Myu, and Masayuki
Taro (green jacket): A boy who hangs out in Cyberia. He hangs around with his friends Myu-Myu and Masayuki. He once asked Lain on a date. Later Lain comes to him for help and advice. He is an unofficial member of the Knights, therefore he knows a lot about Navis.
Myu-Myu: A young girl who hangs out with Taro and Masayuki at Cyberia. She has a crush on Taro and gets jealous when Taro flirts with Lain.
Masayuki: He hangs around with Taro and Myu-Myu. He seems to be Taro's good friend and thinks of Myu-Myu as an annoyance.
DJ J.J.
J.J. is the Cyberia DJ. He seems to know Lain pretty well, at least he knows the Wired Lain pretty well. He often helps the real Lain out by sending her info she asks for.
Carl and the short guy
Carl and his short, dark haired partner are the MIB (Men in Black. No, they're not part of the alien fighting MIB, they are just called the MIB because they were black suits.) Carl is tall with red hair, a short beard, and pale blue eyes. The short guy is short with dark hair slicked back in a short ponytail. Carl does most of the talking and the short guy takes most of the damage that comes their way... They were sent to watch Lain and her activities with the Wired. They wear funny eye sets that gives the special vision. In the center of their eye sets is a red laser beam. (I don't know why its there.) They visit Lain and talk to her a few times.
Masami Eiri
A former employee of Tachibana Lab. He developed Protocol 7 and committed suicide so he could become "god" of the Wired.
The Knights
The Knights are a group of super hackers on the Wired. They are intelligent and a followers of Masami Eiri. The members of the Knights live all over the world. In the series we are introduced to 3 Knights members; a business man, Takuyoshi Masuoka, a housewife, and a fat computer geek.