Kotoko is a hot-headed girl who loves "adorbs" things. She collects them and seems even slightly obsessed with the concept.

Kotoko also has an odd speech pattern as she often starts to list off-topic facts she finds interesting in the middle of conversation. Sometimes they're vaguely related to the topic (for example, if the topic is too long speeches, she starts to talk about how things like elephant's nose and giraffe necks are also too long). Even still, her speech is clear and focused, unlike in the case of Jataro Kemuri.

Kotoko acts cheerful, polite and happy. However, she is mentioned to have a bullying nature and she can be very mean and cruel. She is very mean to Jataro, even more than the others are, and she likes to tease Nagisa Shingetsu. However, she constantly tries to stay on Monaca Towa's good side and praises her a lot.

Kotoko seemingly loved her stage life, but she doesn't like to talk about it and considers it a thing far in the past. She was pampered a lot and now has quite strict, demanding personality. She also has a habit of curtsying and being rather dramatic, which also hints at her past as an actress. It's actually heavily implied that a lot of Kotoko's behavior is just an act and, being the former Li'l Ultimate Drama, she is very skilled at acting. The official artbook implies that her "cutesy" personality might be a front created as a coping mechanism and she herself mentions that she has to keep acting or else she becomes miserable.

Kotoko is one of the more intelligent members of the group, capable of acting cunning and understanding things a bit faster than some other kids. She was able to trick Monaca with her acting and began to act more independently after Monaca was revealed to be a traitor. Still, even though she never really liked Monaca, she was manipulated by Junko to the point that she truly believed she cared about her and the others.

Due to her trauma caused by sexual abuse, Kotoko has a trigger for the word "gentle" (優しい yasashii), as the men who abused her had said they would be "gentle". When she hears this word, she becomes neurotic, and begins crying and screaming in fear, unable to calm herself down except when somebody tells her that they will not be gentle with her. Supposedly because of Junko's teachings, she wants to make other "adorbs" girls suffer what she went through, exclusively the older ones she considers Demons. She is bitter because nobody helped her in the past and thus very paranoid of adults, believing they're all pedophiles.