Because sea levels have surged dramatically, humans have lost a large portion of livable territory, compelling them to depend on existing technology for survival. Among those hit by this calamity is Natsuki Ikaruga, a talented new graduate who lost a leg in a submarine mishap and now endures a bleak existence on a nearly abandoned island. When Natsuki meets an enigmatic woman called Catherine, he discovers an advanced humanoid machine that once belonged to his grandmother Nonko, a celebrated climatologist. The recovered robot, named Atri and fashioned like a young girl, tells Natsuki that Nonko has assigned her a vital task, though she cannot recall its details. Initially Natsuki intended to sell Atri, but the chance to tap into his grandmother"s studies through the robot makes him reconsider. He had previously given up his own aspirations to join a prestigious scientific expedition, yet by sharing with the islanders he realizes he can still influence this barren world. Through his purpose, Natsuki begins to rebuild hope for the community, using Atri"s capabilities to restore ecosystems and document climate data.
