The former world was shattered by the war between humans and demon-kin. The only surviving royal of the defeated demons is the Demon Lord's daughter, Daqne, who returns to these former demon-controlled lands...

Having been born in a secret government laboratory that cultivated esper (telepathic) powers within humans, Shuuichi and two sisters, Sumire and Katsumi, are forced to endure a difficult life as test subjects...