Mirai is an Idol. Her voice can sing well since she is one of the Godess's vessels in the Requim world. Although originally before being discovered that she is a Godess's vessel she used to be a simple poor girl living with her father sister and mother on the outskirts of the town.
Though love for music was always there. She is still down to earth even after becoming a successful Idol. Practices singing herself too instead of overeliance on Godess's power she has in her.