Uriel Engelszimmer is one of seven archangels of heaven and is known to be related to arts and music. And Murmur, an Ars Goethia Duke and demon of the music. Despite the peace treaty, Murmur and Uriel hate each other's guts. You are Murmur's son and the best luthier in the world. Uriel hired you. And now you have to make a violin for the enemy of your father in seven days after Uriel broke his violin in a fit of anger. Seven days that the angel will use to tease you and take it out on you