Murai is a seventeen-year-old second-year student at Takebe Gakuen High School, enrolled in the college preparatory course and consistently achieving top grades in his grade. His background as a high-achieving, academically serious student contrasts with his deeply eccentric personal life, as he harbors an intense and single-minded romantic obsession with his homeroom teacher, Ayano Tanaka. He is described as having a pure, earnest, and sincere personality, though his actions are often wildly unconventional. His perseverance is notable; after Tanaka rejects his initial confession by stating she has no interest in men with long, black hair, Murai undergoes an immediate and dramatic transformation, cutting and dyeing his hair short and blond to perfectly mirror the appearance of Hitotose, the fictional character from the otome game Feudal Era Love Scroll that Tanaka secretly adores.

His primary motivation is to win Tanaka’s love and attention, which drives the central plot of the story. He employs persistent, bold, and often amusingly aggressive methods to court her, frequently appearing in cosplay and staging scenarios that imitate the game’s scenarios. Despite the teacher-student dynamic and Tanaka’s initial resistance, Murai remains undeterred and adapts his approach based on her reactions, showing a strategic if obsessive side to his character. His role in the narrative is that of the relentless protagonist whose actions force Tanaka out of her solitary otaku shell and into increasingly chaotic, often comedic, situations.

Murai’s key relationships center on his friends and allies at school. His best friends, Kiriyama and Hirai, support his romantic efforts with advice and practical help, often providing comic relief themselves. The Nishifuji sisters, Yuka and Hitomi, are enthusiastic fans of his transformation and act as a de facto support group, using their skills in cosplay and art to assist his schemes. Meanwhile, his relationship with Tanaka evolves from one-sided pursuit to a more complex dynamic where both begin to influence each other’s worldviews, though the romantic power balance remains a core tension throughout the series.

Over the course of the story, Murai experiences subtle development. While his devotion to Tanaka never wavers, he gradually gains a deeper understanding of her personal passions and the isolation she feels as a closeted otaku. This growth is expressed not through changing his own feelings, but through a more nuanced approach to winning her heart—learning to respect her boundaries while still pushing them. His notable abilities include high academic performance, which is often used as a plot point to negotiate time or privileges with school authorities, and an almost supernatural determination that allows him to maintain his appearance and role as a Hitotose lookalike without breaking character, even under social pressure or embarrassment. He also demonstrates a talent for quick physical transformations and improvisation, enabling him to adapt to the various scenarios Tanaka’s secret fandom creates.