Zed is a 15-year-old boy who lives in Calm. He is frustrated by his current daily life and feels that somewhere out there is a place where he can live more fully. One day, at the invitation of a mysterious wind, Zed dives into a space-time crevasse, seeking the answer that might be there.

Riding on the wind, he arrives in a world where warriors called Shard Casters fight endlessly with each other, using magical crystals called Shards.

With the power of the Shards, the Shard Casters are able to use magic and control monsters called Spirits. Fascinated by that power, Zed also aims to become a Shard Caster. However, he still doesn't know that residing in his body is Amil Gaul, a mighty Spirit with the power to influence the world's future.