Rather childlike, he tends to complain when he doesn't get what he wants and can be irresponsible, at one point when on the run with Rock, he spent most of their money on an anime figurine. In addition, he states he doesn't know how to get a job or earn money. He prefers playing around with his friends and watching anime above all else. Later on, Nico appears to have an alternate personality when Nico's medicine wears off. Nico becomes crazed, and out of control. Nico then addresses himself as 'Nico' rather than 'I' or 'me'. In this persona, Nico has no limits to his strength and speed, causing great harm to his body. Nico is also attracted to the smell of medicine, charging at people for medicine to save his life as he views the medicine as his lifeline.