"Lain" refers to the anime series titled "Serial Experiments Lain," which was released in 1998. The story follows a teenage girl named Lain Iwakura who becomes increasingly immersed in a virtual world called the Wired. As she explores this digital realm, she grapples with themes of identity, reality, and consciousness. The series is known for its complex narrative and philosophical questions about technology and human connection. It has gained a cult following and is often discussed in relation to cyberpunk and postmodern themes, influencing various aspects of popular culture and media.