Natsuki appears to be a brash, blunt, cranky, and seemingly arrogant girl at first, with a cute, softer interior as a result of insecurity, convincing Monika enough to class her as the embodiment of a tsundere. While she is impulsive and can speak without thinking, Natsuki truly cares about her friends and, even when she has obvious anger issues, doesn't enjoy fights or arguments with people. Over the course of the game, it is shown that she worries about Yuri, and, on one occasion, gives the protagonist a note asking him to help Yuri, fearing that if she spoke out then it would cause more arguments. Natsuki is very stubborn and has a hard time expressing how she feels and what she wants. When repeatedly challenged, she often becomes awkward and tongue-tied, then aggressive, and then simply bursts into tears.

Natsuki is also shown to be less pushy and more relaxed when she is outside of school, as mentioned by the protagonist when she visits his home. She is also known to be skilled in baking, as she made delicious cupcakes for when the main character first arrives in the Literature Club, and for the festival.