Caligula

Tadashi Satomi is a virtual idol known as μ who performs user-inputted songs and gains self-awareness through exposure to users' bitter feelings and dissatisfaction toward reality. Wanting to save humanity — which she believes is continuously suffering — she lures people to a virtual reality world called Mobius with her songs. She then imprisons them in Mobius, thinking they will be free from the suffering of reality and that all their wishes will come true. Nine members of the "Going Home Club," a club that was formed because the characters want to escape from Mobius and go home, try to find a way out.

Synopsis from Anime News Network