Egumi Legacy

In the anime, there exists a floating island in the ocean called Egu Island. On the island, the only entertainment is a songstress named "End of the World." The inhabitants of the island spend their days entranced by her singing. But one day their lives are upended by the disappearance of End of the World. Afterward, the island overflows with anger, doubt, and anxiety. A great war breaks out over End of the World and the Egumi Legacy.