Her Persona is Sakuna-Hikona. Sakuna-Hikona who appeals to be a super detective. Yamato-Takeru is the evolve or next stage of her former persona Sakuna-Hikona. Her persona specializes in Light (Hama) and Dark skills (Mudo). As such Naoto can be a complete threat to any team. This was slightly modified in Persona 4 Golden where she is given the opportunity to learn the more powerful Agi, Zio, Bufu, and Garu single spells.
Naoto's parents died in a car accident when she was still very young, and has been looked after, and still in the care of her Grandfather ever since. She has no other know relatives. Because of the accident, Naoto has suffered a great deal in her social life, not making regular friends. Instead she focused on detective novel's and improving her own detective prowess making that gap even larger. She also admires her Grandfather, Mother and Father as they were all skilled dectectives in their day and age. She aspires to one day be the detective that her family can be proud of.