A voice called in the light. It sang songs of fire, water, earth, wind, and life. From it, all things are born.
Another voice called from the darkness. It only sang of death and decay. From it, all things die. All things end. All things rot. All things decay.

Rell is an average Holy Knight assigned to the legendary Squad Seven. Their primary mission is to defeat Shadows, strange translucent beasts that are driven to kill as many people as possible. He fights under the hero Alicia, the supposed destined hero who has the power of all five elemental Nin at her disposal. Meanwhile Rell is only capable of using Shadow Nin, a rare but ultimately unremarkable form of Nin. Rell sets out to unravel the secrets of the Shadows, a secret that just may shake the very foundations of creation itself.