Sareki Oukoku

The world, now covered in sand, is where a war is raged between the humans and the cause of earth's destruction, the Sandbiters. The Sandbiters devour humans and control sand dragons. Only the Kingdom of Time remains, protected by the Water Goddess. Kirameki is heir to the kingdom. In his youth, Kirameki wondered into the desert and met Saga, a Sandbiter. Eight years later, when Kira is a teenager, a Sandbiter infiltrates the Kingdom. The infiltrator is Saga, Kira's half-brother and childhood playmate, who begins to try to take over the Kingdom of Time.

(Source: ANN)

Included one-shot:
Jikan wo Tometa Shounen-tachi