While walking home from school, "Shu", the main protagonist and a boy who loves kendo, intercedes to protect a girl, Lala-Ru, who is attacked by abductors piloting dragon-like mechas and is accidentally transported to the attackers' world as a result—a wasteland devoid of water and dominated by a red giant star. Lala-Ru possesses a pendant containing a vast reservoir of water, and she has the ability to control it.
