Natsuki is a brash, blunt, cranky, seemingly arrogant girl with a cute, softer interior as a result of insecurity. 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, we see 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 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.

Her cute interior also involves a love of manga, particularly those in the slice-of-life genre, and baking. She has been known to store her manga collection in the Literature Club out of embarrassment, and while the rest of the club obviously knows about her interest, she is still hesitant to talk about it. Natsuki also likes cute things, like cupcakes with cat faces. She also likes poems with cuter, happier words, though her own poems are still about sad things, such as being persecuted for your hobbies. Her simplistic writing style puts her at odds with Yuri.

Natsuki dislikes being called "cute," even when she acts as such, or does cute things, and will deny any claims from others relating to this, nevertheless she is much more comfortable exposing her sweet side once she knows people aren't going to tease her about it. Natsuki hates it if she isn't taken seriously, whether it's her writing, her hobbies, or just her overall demeanor. It is likely Natsuki learned to be ashamed of herself and her hobbies, because her classmates judge her and her implied abusive father, making her abrasive nature a coping mechanism. This is also implied in her secret poem, "Things I Like About Papa".

It is shown that she is a very lonely person who desperately craves affection. One example is during the third poetry-sharing session. If Natsuki has liked all your poems to date, she outright asks the protagonist if he thinks her poems are the best, which swiftly shifts to her begging him to say they are, even if he hates them.