Kemurikusa

In a desolate world filled with ruined buildings, giant mechanical bugs and a sea of poisonous red fog that blankets the land, a band of sisters travels from island to island. The girls are aided by the power of Kemurikusa, mysterious glowing leaves that their plant Midori produces, but the water they need to keep themselves and Midori alive is getting difficult to find. When they encounter a man who has lost his memory on their travels, they are suspicious of the fact that his body chemistry is nothing like their own; but their new companion is fascinated with Kemurikusa and ends up joining them on their quest for survival. What awaits them in this strange world?