Murakami's childhood was marked by his fascination with Kuroneko, a girl who claimed to have met aliens, but was dismissed by everyone. After her tragic death, Murakami was left severely injured and haunted by a promise he made to find proof of alien existence. Years later, the arrival of a new classmate, Kurohaneko, who resembles Kuroneko, sparks a quest to uncover the truth.

A long-lost best friend's doppelganger appears at Murakami's school, reviving...