In 2017, two organizations are fighting over territory. Mana is an orphan born to a family of extraordinary power, abilities that can be unleashed through song. However, Mana promised her elder brother, who moved away 10 years ago, that she would keep this power a secret.

Mana lived happily in the orphanage until she turned seventeen, the age at which all orphans must leave. She had planned to travel to the city to find her brother. Instead, the orphanage owner drugged her. Mana woke up in an strange camp, where it turns out that she was being sold as people with powers fetch a high price.

As panic set in, a mysterious man named Gilford appeared and purchased her. He brought her to a large house near the city and announced that she was now a member of an organization of individuals with special abilities. What will the future hold for Mana?

[Edited from Liemyx's blog]