Lain Iwakura

Lain Iwakura (岩倉 玲音 Iwakura Rein) is the main protagonist and titular character of Serial Experiments Lain.

She is introduced as a shy Japanese girl in middle school at the beginning of the show

After receiving an e-mail from Chisa Yomoda who had committed suicide, Lain discovers the virtual world of The Wired. Throughout the series, Lain is subjected to hallucinations by the Knights in order to make her lose her sense of self and attempt to find solace in the Wired, in order to fulfill the Knights' prophecy of the arrival of the goddess of the Wired.

Appearance
Lain appears to be a 14-year-old girl and stands at a shorter height than most of the characters in the show. She has pale skin, brown eyes and brown hair. Her hair is short, left slightly above the shoulders and a long lock of hair on the left side of her face. She wears a yellow hair-clip throughout the show. The hair-clip is 'X' shaped and wraps the entire lock of hair securely. Throughout the show, Lain could be seen in her school uniform, which consists of a grey blazer, with a blouse and a red tie underneath, a green skirt and white indoor shoes accompanied by black socks. When she is not in her school uniform, she either wears her pajamas, which are stylized to look like a bear or plain clothes. Some characters in the Cyberia club have also mentioned that she dresses like 'an innocent schoolgirl'.

Personality
Lain is quiet and doesn't talk much, which leads to her being a bit of a social outcast in contrast to the rest of her classmates, always dissociating herself from big crowds and is shown to be rather shy, and does not seem to talk as much as her other classmates while overall being a very genuine and kind person. Her eyes are soft and naive and her posture is slumped depicting her introverted personality. She often hallucinates and sees things that aren’t real. At one point she thinks that steam is coming out of her hands, during an interview director Chiaki J. Konaka said that this means that she's mentally ill.

Lain of the Wired
One time called the "Wild Lain" by Taro. She's a different persona of Lain that appears most of the time when Lain is investigating the Wired. She's no longer the introverted person that she usually is. She has an offensive attitude, an erect posture, and she's all wide-eyed and alert. She exudes self-confidence and thrives on facts over emotion.

The Third Lain
Appearing in the fifth and the eighth episodes. Her half-lidded eyes and casual posture demonstrates a new more laid-back persona of Lain. As she only appears to torment Alice and Mika in the series, she's shown as a more vicious, ill-intentioned persona than the others. Some clues in the series may lead viewers to think that she was her own entity created by the Knights to cut from the original Lain anything that could make her want to stay in the real world.

The Fourth Lain
Appearing in the final episode. It's not clear if she is another one of Lain's personas or her own entity. She appears more serene than the other personas. She is confident about what she knows, playing a guide trying to convince Lain to embrace her godly nature.

Alice Mizuki
Alice is the first to attempt to help Lain socialize by taking her to a nightclub, and from this point always tries to protect and take care of her.

Chisa Yomoda
Chisa went to the same school as Lain and both were in the same grade. After her suicide, Chisa sent mail to her entire school including Lain. Lain responded to the mail and started to chat with Chisa about the Wired. This chat sparked Lain's interest of the Wired. After the chat, Chisa appeared before Lain two times but disappeared each time before having a conversation with her.

Yasuo Iwakura
Lain's father-daughter relationship with her "father" is more calm and collected as she gradually learns more about herself and her extraordinarily strong and deep affinity with the Wired itself. He is the very first person she turns to in wanting to test her newly improved Navi's personal computer and software. She later disregards his warning of not confusing the real world with the virtual one; the latter being nothing more than an ever evolved form of communication worldwide. She assured him that she will be able to further blur the invisible line between the two and go into it more freely, consciousness/mind and all, without requiring any devices, expressing his uncertainty of whether Lain remains the girl he knows.

Mika Iwakura
At first, Mika seems to be judgmental and rude towards her younger sibling, Lain. After a while, Mika seems to care and show more interest and became obsessed, leading to her downfall where she later loses her sanity.

Trivia

 * She was designed to look like her Japanese voice actress Kaori Shimizu.
 * Minor edit source: https://twitter.com/lainscreens