Doppio thinks of himself as the most loyal subordinate to Diavolo, his boss. He will go great lengths for him, even if the situations he ends up in make him panic greatly at first, he can overcome anything for his boss, determined to make himself useful to him, as Diavolo is a very important person for him. However, he's not a very confident person, and he's ashamed of his rather clumsy and unfortunate nature.