Megumi Nishitori is a fifteen-year-old girl and a close friend of the protagonist, Shuri Komori, in the anime Komori-san Can't Decline. She has known Shuri since elementary school, and their friendship forms the core of her daily life. Megumi is a student in the same class as Shuri, and the two have been placed together for three consecutive years due to the school's annual class reshuffling. She is a member of the broadcasting committee in her third year.

Physically, Megumi has a notable and distinct appearance. She has blonde, waist-length hair often styled in twintails and blue eyes. Her character design includes a single visible fang, which adds to her expressive and lively demeanor. She is typically seen wearing her school uniform along with leg warmers.

On the surface, Megumi comes across as bright, energetic, and slightly flashy in her behavior. However, this exterior belies a more introverted and shy nature. Despite her social and sometimes bold appearance, she is actually quite timid, to the point of fearing being spoken to by strangers and even feeling anxious about entering a public bath. This contrast between her looks and her true personality is a defining aspect of her character.

Her primary personality trait is her pronounced laziness and a strong tendency to be overly reliant on her friend Shuri. Megumi has a well-established habit of asking Shuri for help with tasks she finds troublesome, most frequently her school homework. While she excels exceptionally well in English, a skill she developed as a returnee student, her academic performance in all other subjects is described as being disastrously poor. Consequently, she is the person who most often turns to Shuri with requests for assistance, particularly with homework assignments. Beyond academics, her interests lie in anime and video games, and she has a strong dislike for studying.

The dynamic between Megumi and Shuri is the most significant relationship in her life. They have been close friends since Shuri transferred to their elementary school in the fifth grade. Their friendship was solidified during a difficult time for Shuri, who was struggling to adjust to a new school after being separated from previous friends due to a move. When Shuri was feeling down and was taken to the nurse's office, Megumi was the one who accompanied her, creating a deep bond of trust and reliance. In the present, this manifests as Megumi frequently leaning on Shuri's inability to decline requests, often taking advantage of her friend's kindness for her own convenience.

Megumi is also friends with Masako Negishi, another of Shuri's close companions from middle school. While the trio forms a solid friend group, Megumi's dynamic with the more cynical Masako often contrasts with her own more dependent relationship with Shuri. Her role in the story is primarily to act as a catalyst for many of Shuri's good-natured errands and tasks, and to serve as a foil that highlights Shuri's endlessly giving personality. Her laziness and reliance create many of the comedic situations, but they are always rooted in a genuine, long-standing friendship.

Over the course of the narrative, Megumi does not undergo a dramatic personal transformation. Instead, her development is subtle, primarily reinforcing her established traits. She remains consistently lazy and reliant on Shuri, yet her loyalty and the deep history she shares with her friends are always evident. Her abilities are limited to her strong command of the English language, though she rarely applies this skill outside of an academic context. In a broader sense, she possesses the unique ability to consistently elicit Shuri's help, a skill born from years of knowing exactly how to make a request to a friend who cannot say no. In a minor piece of background information, it is noted that she is the niece of a character from other works by the same creator.