Masamichi Fujisawa is a history teacher at Shinonome High School, a man whose appearance matches his casual approach to life. He is tall and thin, with a mop of scraggly dark hair and a perpetual stubble, and he dresses for comfort rather than style, typically wearing a warm-up suit and sandals. Despite his unkempt look and his reputation among students as someone not widely respected, Fujisawa possesses a deep and genuine devotion to his students and a very strong sense of school spirit. His dedication to teaching is matched only by his three principal vices and hobbies: smoking, drinking, and mountain climbing.

Fujisawa is fundamentally a good-hearted individual with a romantic and idealistic view of the world. He sees matters in terms of right and wrong and desires to act as a noble, brave, and chivalric hero who sets a good example for his students. He is fearless, honorable, and inventive, but his biggest flaws are his addictions to alcohol and tobacco. He is almost never without a cigarette and becomes irritable if he cannot drink daily. When deprived of both, the combined stress triggers a dramatic amplification of his abilities.

When he is transported to the world of El-Hazard along with his students Makoto Mizuhara, Katsuhiko Jinnai, and Nanami Jinnai, Fujisawa gains superhuman strength and athletic ability. This power is directly linked to his sobriety: he loses his enhanced strength if he has consumed alcohol, and if he abstains from both alcohol and nicotine, his power escalates into what is often called the "Hyper Fujisawa" state. In this state, his strength becomes immense, allowing him to lift several tons, punch Bugrom soldiers great distances, leap enormous distances, and generate a protective red energy field. His mountaineering expertise also proves useful for climbing sheer cliffs in the fantasy landscape.

In the story, Fujisawa first encounters Makoto in El-Hazard and together they rescue Princess Rune Venus of Roshtaria from Bugrom attackers. From that point, he accompanies Makoto on his quest to find Princess Fatora and later to stop the rogue Eye of God. He serves as a loyal ally and protector, often providing comic relief with his struggles to maintain his sobriety while also demonstrating genuine bravery and strength in battle. His key relationship outside his students is with Miz Mishtal, the Water Priestess. After he rescues her from what he mistakes for a monster, Miz instantly falls in love with him and becomes determined to marry him, an idea that Fujisawa at first finds awkward and avoids. Over time, however, he grows to care for her and eventually accepts the relationship, and in later series they are married.

Fujisawa's development across the franchise shows him gradually overcoming his worst vices. In the original OVA, he remains a heavy drinker and smoker, but by the time of the sequel series, he has largely given up those habits, carving out a respectable life in El-Hazard as a teacher, war hero, and husband. In the alternate timeline of the television series El-Hazard: The Wanderers, his character is very similar, though he is not a smoker, so the Hyper Fujisawa state does not exist in that continuity, and his love of mountain climbing is emphasized more. Throughout all versions, his core motivation remains the protection and well-being of his students, his strong sense of duty, and his desire to uphold the honor of Shinonome High School.