Arve Rezzle: Mechanized Fairies

Set in 2022, the story delves into a world where nanomachines allow for the integration of the human nervous system with external networks. Individuals leave their physical bodies behind in water tanks while navigating cyberspace. However, a crisis named "Early Rapture" threatens this digital existence, causing numerous consciousnesses to be lost within the network.

The protagonist, Remu Mikage, embarks on a quest to find his sister Shiki, who has fallen victim to this crisis. Upon visiting her apartment, he discovers that the entity he encounters is not his sister but a being that has taken over her body. This intriguing premise raises questions about identity and reality in a technologically driven society, making it a noteworthy title in the anime genre.