"Incomplete world, we need you for the safety of our citizens here." Eternal ONE begins with the story of Lucio City, who is said to be somewhere in the Pacific Ocean. Its secret organization SBLC; Security Bereau of Lucio City is an organization that conducts suspicious commissions in the city and keeps citizens and cities safe. Please become our Mr. Admin of the SBLC and dig into the secrets of Lucio City and save citizens from unknown threats!