Serial Experiments Lain (1998)

Serial Experiments Lain is a thought-provoking and surreal anime that explores themes of technology, identity, and reality. It follows the story of a lonely and introverted girl named Lain who receives mysterious emails that lead her to question the nature of existence and her own identity. As she delves deeper into the world of the internet and virtual reality, Lain discovers dark secrets and confronts mind-bending challenges that blur the line between the real and the virtual.