Masamune Izumi is a teenage boy with green hair and purple eyes. He is most often seen wearing his school uniform, which consists of a white undershirt, a tie, a tan jacket, maroon pants, and brown shoes. Outside of school, he frequently dresses in comfortable, casual clothing, especially while working at home or during trips.

Masamune Izumi is characterized by his strong sense of responsibility and independence. At the age of fourteen, he took it upon himself to care for both his own needs and those of his younger stepsister, Sagiri, who had become a shut-in. His maturity and self-reliance stem largely from this early assumption of adult-like duties.

He has a low tolerance for laziness and is easily irritated by actions that disrupt or upset his sister. While dedicated and hardworking, Masamune struggles with low self-esteem and a fear of rejection. He is highly sensitive to criticism whether about his writing or personal behavior and is deeply concerned about how fans and editors perceive his work. Despite this, he takes great pride in his craft and dreams of one day watching an anime adaptation of his novels with Sagiri.

Masamune is also notably submissive, often giving in to the requests and demands of others without resistance. His deep affection for his sister motivates much of his behavior, and he frequently prioritizes her comfort and happiness above his own.

In his free time, Masamune enjoys spending time at Takasago Tomoe’s bookstore, and he is also a regular visitor at the Crystal Palace, the residence of fellow author Elf Yamada.

Masamune Izumi is a teenager who experienced significant loss early in life. Before the start of the series, he lost his mother and was raised by his father. During his first year of middle school, Masamune entered and won a light novel writing contest, marking the beginning of his career as a light novel author.

Approximately two years later, his father remarried, and Masamune gained a new stepsister, Sagiri Izumi who, unbeknownst to him at the time, was also secretly his illustrator under the pseudonym “Eromanga Sensei.” Shortly after the marriage, Masamune’s father and stepmother left on their honeymoon but tragically never returned, leaving both Masamune and Sagiri orphaned. From that point forward, Masamune took on the responsibility of caring for Sagiri, who had become a hikikomori, while continuing his work as a novelist.

Sagiri Izumi
Sagiri is Masamune’s younger stepsister. Initially unaware of her identity as his anonymous illustrator “Eromanga Sensei,” Masamune is surprised and deeply impressed upon learning the truth. He is fiercely protective of her and works hard to support her, especially after their parents’ disappearance. His primary goal is to help Sagiri overcome her hikikomori lifestyle and encourages her to return to school. After a moment of perceived romantic rejection, Masamune commits himself to being the best older brother he can be, while still harboring admiration and pride for her talent.

Tomoe Takasago
Tomoe is Masamune’s classmate and the only named friend he has at the start of the story. She runs a bookstore with her father, which is Masamune’s favorite place to visit. Tomoe is one of the few people who knew Masamune’s identity as a novelist before Sagiri found out. He values her recommendations, respects her opinion, and often turns to her for advice. She harbors romantic feelings for him.

Ayame Kagurazaka
Ayame is Masamune’s editor. Though Masamune is intimidated by her in her professional role, he tends to disregard her outside of work. He respects her authority as his editor but does not form a particularly close personal relationship with her.

Elf Yamada
Elf is Masamune’s fellow author, next-door neighbor, and literary rival. Their first meeting occurs during an argument with his editor over securing Eromanga’s illustrations. Despite finding her bratty and lazy at times, Masamune respects Elf’s talent and considers her a source of inspiration. Though often exasperated by her behavior, he gradually grows to see her as a close friend. He playfully goes along with her exaggerated self-title as a “best-selling author” and remains a fan of her work, often seeking advice and motivation from her.

Megumi Jinno
Megumi is one of Sagiri’s classmates. While Masamune acknowledges her physical attractiveness, he is annoyed by her flirtatious behavior and manipulative attempts to lure Sagiri out of her room. Initially put off by her over-the-top personality, he later discovers that her bold claims are largely an act used to appear mature and appealing to others. He refers to her teasingly as a “fashion bitch” after learning the truth about her insecurities.

Kotetsu Izumi
Kotetsu is Masamune’s father and Sagiri’s stepfather. Although Kotetsu and Masamune were close, his father’s disappearance along with Masamune’s stepmother left a lasting impact. Masamune continues to think of his father fondly and strives to make him proud, even as he comes to terms with the reality of their loss. It is implied that both parents died in a car accident during their honeymoon.