Caligula

High schooler Ritsu Shikishima likes to spend his quiet days with friends while turning over psychological questions—especially what it means to be happy. That calm starts to fracture when a faint, static-laced voice begs for help. The voice belongs to μ, a wildly popular pop idol whose singing begins to warp reality: familiar faces flicker with glitches and twist into Digiheads, violent creatures that target anyone starting to notice something is deeply wrong.

Ritsu soon discovers the truth—he and the others are trapped inside Mobius, a virtual world created by μ. To survive, he seeks out fellow “awakened” individuals before they’re wiped out, fighting back with weapons and abilities born from their emotions, known as the Catharsis Effect. Standing in their way is a mysterious faction called The Ostinato Musicians, as the group struggles to break free from Mobius.