Megumi Jinno is a classmate of Sagiri Izumi and the class representative for their middle school section. She is approximately twelve to thirteen years old and has a physical appearance that is noted to be exceptionally beautiful, often making her seem older than her actual age. She has wavy ginger hair that is typically tied up in a ponytail with a purple and pink scrunchie, complemented by wide golden eyes. Standing at a height of 140 centimeters, she wears the standard school uniform consisting of a white button-down shirt with a yellow bow, a navy pleated skirt, black knee socks, and brown shoes. Her birthday is June 15th, making her a Gemini, and her blood type is B.

In terms of personality, Megumi is an extremely cheerful, sociable, and perceptive individual who possesses a remarkable ability to befriend a large number of people, having made friends with nearly everyone in her entire grade level. Her presence is so positively overwhelming that Masamune Izumi describes her aura as a holy attribute. She is flirtatious and prone to making bold and provocative statements, such as declaring a fondness for male anatomy or calling herself a provocative nickname, in an attempt to appear cool and sexually experienced. This behavior, however, is revealed to be largely an act. In reality, she has no genuine knowledge or experience regarding such matters; her only exposure to the male body comes from seeing her younger brother while bathing together. When confronted with actual explicit content or situations, her confident facade can crack, leading to discomfort or even tears, revealing her true, more innocent nature.

Megumi's primary role in the story is as a catalyst for social interaction, particularly concerning the reclusive Sagiri. As class representative, she is highly motivated to befriend Sagiri and convince her to attend school. To achieve this, she takes bold actions, such as visiting the Izumi household unannounced and even flirting with Masamune in an attempt to make Sagiri jealous. Her social skills are so effective that she can mobilize her entire class for group initiatives, like collectively going to the Izumi home to encourage Sagiri’s attendance. Beyond her relationship with the Izumi siblings, Megumi is close with Tomoe Takasago, a relationship that is key to her character development. Initially, Megumi dismisses light novels as gross books for geeks, but after receiving recommendations from Tomoe, she becomes an enthusiastic and devoted fan. Megumi is also highly perceptive, and a significant moment in her development is when she independently deduces that the reclusive Sagiri is secretly the famous illustrator known as Eromanga Sensei.

Despite her confident and sometimes deceptive persona, Megumi’s actions are largely driven by a genuine desire for friendship and social connection. Her development throughout the story involves a gradual reveal of her true, less experienced self beneath her fashionable and bold exterior. Her notable abilities are not physical or supernatural but are purely social and psychological. She possesses immense charisma and leadership skills that allow her to influence and bring together large groups of people. She is also a skilled observer, capable of seeing through the facades of others. Ultimately, Megumi Jinno is a friendly and energetic girl whose pushy yet well-meaning nature helps to draw others out of their shells, even as she learns to drop her own act and form genuine friendships.