In a dystopian world ravaged by monstrous Klaxosaurs, humanity survives in mobile cities, relying on giant mechs called Franxx piloted by pairs of boys and girls. ZeroTwo, a mysterious hybrid girl with pink hair and horns, was created in a lab as a weapon. Escaping her tragic past, she searches for her lost 'darling' to pilot the mighty Strelizia Franxx, craving genuine connection amid endless battles.