Darkness falls...

For the first time in eight hundred years, the sun sets on the desert world of Crimson Winter, throwing the planet into unexpected darkness and further chaos. And with the setting of the sun comes the unexpected rise of hordes of undead creatures from the endless Sand Lakes.

...so I can...

Yukari Namikoya, Japanese high school student turned Chosen of Sapphiros, must rise to the occasion and use the powers she has been given to try and protect those she's come to love against overwhelming odds.

...see the light of day again.

But when each night lasts a little longer, Yukari soon realizes that their days might be numbered and a sinister force beyond even the menace of the Vile Emperor might be behind the terrors that are besieging the planet during such a desperate time. The worst part is that Yukari doesn't know if her powers, or even the combined forces of her allies will be enough to protect the Kingdom of Taiyou, let alone the whole world.