Their songs attracts people in the wrong way and each time they sing or hum the song or beat then their souls get eaten but when they sing the girls songs the shield gets stronger and they become safe.
One of the girls Rumi has a secret she has been hiding and no one really knows about it except her adopted mom. Rumi then gets very sick and has to stop making music for a while. She then also looses motivation in making music and nothing sounds right with her and it just over all isn't good but eventually she gets the motivations from one of the demon guys and they help boost her back and she gets motivation again and helps create music and save everyone from the demons.
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