Kujira no Kora wa Sajou ni Utau

Chakuro is the archivist for the Mud Whale, diligently chronicling the lives and deaths of his people. As one of the short-lived thymia wielders, he knows his time is limited and is determined to leave a better record than his predecessors. But the steady pace of their isolated existence on the Mud Whale is abruptly shattered when a scouting party discovers a mysterious young girl who seems to know more about their home than they do…
(Source: Viz Media)
Notes: Nominated to the 21st Annual Tezuka Osamu Cultural Prize.