Zero Two was the main heroine and the deuteragonist of DARLING in the FRANXX. She was a human-klaxo sapiens hybrid and a member of the APE Special Force fighting on the front lines. An elite Parasite with the codename “002” who was also known as the “Partner Killer”, Zero Two had always accepted solitude due to her horns and Klaxosaur blood. Despite having no regard for human life or her own and being used to fight alone, she took an interest in Hiro and decided to give him a chance to pilot with her, making him her new partner and “darling”. After Hiro was able to ride with her more than three times, the pair became the 13th Plantation’s newest members, piloting a FRANXX called Strelizia.
Over the time spent together, Zero Two came to develop special feelings towards Hiro, but her determination to become human coupled with Hiro’s apparent fear of her increasingly feral characteristics made her begin seeing him as nothing more than an outlet to become human. When their relationship as partners began to take a turn and slowly crumble, she remembered her forgotten feelings of love towards Hiro during childhood along with her current feelings. The two eventually became a couple before their demise.