Having lost both her parents in a car accident when she was very young Naoto acts very mature in spite of her age. As a descendant of a respected lineage of famous detectives she wears formal clothing, and deepens her voice when she speaks in a sophisticated, stilted manner. Naoto has difficulty making friends and is lonely as a result. Her biggest insecurity is her gender as well as her age. She yearns to be seen as an adult, and expresses frustration at being treated like a child by the police force. She hates being looked down upon, and fears no one will take her seriously as a female in a sexist occupation field. Naoto is ashamed of being female. Despite her mature nature, Naoto has a shy side to her. And when in a state of fear and/or panic, her voice becomes more feminine than usual, possibly meaning she only has a masculine voice when she is composed.