Naomi is generally a bright and cheerful, if stubborn, teenage girl. A tomboy, she often feels the need to take charge of everything she is involved with, which usually causes her to butt heads with Satoshi Mochida. This behavior hides a more "girlish" side to her that enjoys shopping and grooming herself like other average girls of her age, which shows itself whenever she plays with her best friend Seiko Shinohara. She also tends to let her emotions control her actions: when stressed, she is prone to acting like a spoiled child who whines, complains, and lashes out at everyone around her. However, she is very self-aware of herself during such intervals, but has extreme difficulty stopping herself from acting in such an immature manner, which causes her to feel guilty whenever she regains control of herself.