Lain Iwakura 岩倉 玲音 (Iwakura Rein)
Lain is a withdrawn fourteen-year-old junior high school student who barely uses her old children's NAVI until she receives an email from a classmate who has just killed herself. Curious, she asks her father for a new machine and turns out to have an uncanny talent for it, rebuilding her room into a humming tower of hardware. At the same time people start seeing 'another Lain' at the Cyberia club, bold and mocking, and her sense of who she is begins to slip. Her look grew out of a group process: ABe drew many sketches until the team agreed on her, Ueda asked for the single long left lock to break symmetry (in his words, to keep voices out of her left ear), ABe added the X-shaped clip, and Kishida gave her the bear pajamas that work as armor at home. Konaka's scripts split her into a shy Lain, a confident Lain in the Wired and a cruel prankster Lain, and Kaori Shimizu, then fifteen, says the scripts marked each with a different spelling. Ueda deliberately cast an untrained, uncertain voice for her.
More (spoilers)
Lain learns that she was not born to the Iwakuras: she is a being that took shape in the Wired, and her family were placed to watch her. Masami Eiri claims he made her and wants to be her god, but she rejects him. Seeing the Wired and the real world bleed together and hurt the people she loves, she resets everything and erases herself from everyone's memory. Ueda put it plainly at Otakon 2000: after the reset she is simply gone. In the last scene she meets a grown-up Alice, who half recognizes her, then speaks to the viewer; ABe drew that final close-up at Konaka's suggestion.
Sources: en.wikipedia.org archived · ja.wikipedia.org archived · animenewsnetwork.com archived · konaka.com archived · lawmune.net · lawmune.net · lawmune.net · gigazine.net · lain.wiki