Caligula

A virtual reality program named "Mobius" allows individuals to escape their real-world suffering by immersing them in a high school environment they cannot leave. A group of users discovers the artificial nature of their world and bands together as the "Go-Home Club," seeking to escape and confront the system's controlling entity, a program known as "μ." They face opposition from the "Ostinato Musicians," a faction that supports μ and views the Go-Home Club as a threat.