The region of Metafalss surrounds Infel Pira; the second Tower; which is said to represent the Goddess Frelia of the Trio A mysterious epidemic called Infel Pira Dependency (IPD) has been killing Reyvateils. Croix; a young knight from the Church of Pastalia; is sent to contain the epidemic. However; many more challenges await which lead him to unraveling the mysteries of the planet Ar Ciel and seek the legend handed down by the people of Metafalss: the lost Song of Metafalica.
- Cosmoshphere: Ar tonelico features a revolutionary system that combines character development with skill acquisition. By diving into the Reyvateil’s subconscious world one gets to know the character of the team member better while acquiring new spells.
- Song Magic: When the fronline attacks an enemy the song magic gauge increases. After a certain level the Reyvateils are able to cast a powerful magic attack by singing.
- Replakia: Song magic can be powered up by Replakia which are replicas of Reyvateils you have saved. The more Replakias you have the stronger and more unique your song magic becomes.
- Syncrinity: In this latest installment song magic is cast by 2 Reyvateils. If their emotions are more closely synced the stronger the magic becomes.
- Emotion Gauge: During battle how well you cheer your Reyvateil becomes the key to victory.