Kujira no Kora wa Sajou ni Utau

A 14-year-old boy named Chakuro serves as the archivist of the Mud Whale, a nearly utopian island that drifts over an endless sea of sand. Most of the island's residents possess saimia, extraordinary abilities that come with the cost of shortened lifespans. Chakuro and his companions have encountered other islands, yet they have never encountered anyone outside their own community. During a visit to an island as large as the Mud Whale, Chakuro meets a girl who alters the course of his life.