Monika's alterations backfire because Sayori's increased depression level causes her to confess her love to the main character in an attempt to find happiness, then commit suicide the next day, regardless of the choice the player made. She starts with Sayori as she viewed her as the largest threat because she was the main character's childhood friend. In desperation, Monika begins trying to make the other girls unlikable by altering their traits, as she only had the ability to edit variables within the game and did not want to delete/kill the other girls right away because of her lingering attachment to them. She begins taking drastic measures when the other girls prevented the player from being able to spend time with her during the scene in Act 1 where the player has to choose a girl to help for the festival. However, it is later revealed that at some time before the start of the game, she underwent an epiphany which made her discover that she was in a game and also granted her the ability to edit the game's variables, changing her attitude towards the other girls because she knew they were not 'real'.

She openly displays care and concern for her club mates, praising each member's writing style and even comparing them to famous authors and poets. Monika was originally a very considerate and kind person who was always thinking about the needs of other people. She also has a passion for piano, which she practices frequently after school. She aspires for the Literature Club to be a place to showcase and grow everyone's passion for literature. The Literature Club, which she founded after leaving the Debate Club, is very important to her. Monika had previously been a part of the Debate Club but left due to all the inner politics and drama, highlighting a desire for order, freedom of topics and friendliness. She is always depicted as mature and hardworking, with a serene, compassionate expression on her face. Monika is also known to be highly popular, which makes the protagonist admire her. She is not as talkative as the other girls, but it is hinted that this is not by choice. The other characters describe Monika as intelligent, confident, and athletic. She wears the standard issue female school uniform consisting of a warm gray blazer fully buttoned and untucked, brown sweater vest, white shirt fully buttoned and tucked, red ribbon, dark blue pleated skirt, black thigh-high socks and white uwabaki slippers with pink tips. She is of average height and the second tallest character, behind Yuri or the protagonist.

Like the other female characters, she has two prominent strands of hair beside her bangs that reach slightly past her chest. Monika has extensively long coral brown hair that she keeps tied up in a high ponytail tied back with a large white bow, curled slightly at the ends.

Monika after story oki doki