It is the year 2115. Tohru Kazasumi lives a boring school life in the 17th Far East Imperial City Management District. One morning, he awakens from a strange dream. The streets are filled with talk of the "Desert Syndrome", a mysterious phenomenon where humans crumble away like sand; but for Tohru, who is calm about any event, felt it had nothing to do with him. After school that day, while walking home with his classmate Kyoka Katagiri, he finds the mysterious girl from his dream at the side of the road. She suddenly runs off and Tohru rushes after her; but from that day, his life takes a drastic turn...