Shikishima Ritsu was living a fulfilling high school life; then one day, when Ritsu heard the new song from pop idol, μ, he noticed a cry for help hiding within the song.

Ritsu is attacked by students taking on strange shapes, but Satake Shogo saves him with a giant handgun; lost and confused, Ritsu returns home to his mother, who is now covered in static and repeating the same lines.

After talking to Ritsu about the truth of their world, Aria and Shogo ask him for his aid.

Ritsu and a few others accept Mizuguchi Marie's invitation to the marine resort, Sea Paraiso, within Mobius.

μ's voice echoes throughout the city while the Musicians attack Ritsu and the Digiheads.