 Hiro was very jovial, optimistic, hopeful, helpful, tenacious and brave, he has blue horns, and he used to have blue skin, he is also a demon, just like zero two, but he appears as a human, being borned normal, but he wants to change that, and zero two calls him "darling", and Hiro and zero two had a good life when they were little, but their memories got erased, but now they got the memories back, he likes riding franxxs, but he failed his pilot degree, but now he rides a FRANXX with zero two.