Go Nagai, born Kiyoshi Nagai on September 6, 1945 in Wajima, Ishikawa Prefecture, is a seminal figure in the manga and anime industries. His career, which began in the late 1960s, has been defined by the creation of numerous iconic franchises and the introduction of concepts that would fundamentally shape the medium, particularly in the super robot and dark fantasy genres.

Nagai's path to becoming a creator was heavily influenced by his early life. After his father's death, his family moved to Tokyo. A severe illness during his preparatory school years made him contemplate his mortality, solidifying his determination to leave a mark through manga, a passion he had held since childhood. He was deeply inspired by the works of Osamu Tezuka, and after creating a prototype for what would later become Black Lion, he became an assistant to the renowned manga artist Shotaro Ishinomori. Nagai made his professional debut in 1967 with the gag comedy Meakashi Polikichi.

The turning point in his career came in 1968 with the serialization of Harenchi Gakuen in the fledgling Shonen Jump magazine. The series, which introduced overt eroticism and toilet humor into a school setting, was a massive commercial success, helping the magazine sell over a million copies. However, it also sparked intense public outcry from parent-teacher associations and women's groups, leading to nationwide debates about morality in comics. This controversy, which included public protests, established Nagai as a provocateur who pushed the boundaries of expression, and the series is now recognized as a pioneering work in the ecchi genre. In response to the criticism, Nagai later steered the manga into darker, more violent territory, culminating in an allegorical ending where the characters are massacred by parental forces.

The 1970s marked a period of unparalleled creative output for Nagai, during which he launched his most enduring and influential properties. In 1972, he began two series that would become cornerstones of anime and manga. Devilman, a dark horror saga about a young man who merges with a demon to fight his own kind, is a landmark work known for its graphic violence, tragic narrative, and exploration of humanity's darker nature. The same year, Mazinger Z redefined the mecha genre. Instead of a giant robot that was remotely controlled or a living entity, Nagai introduced the concept of a piloted robot, with the protagonist controlling the machine from a cockpit within its head. This innovation created the super robot genre and set the template for countless series that followed. Other major works from this period include the shape-shifting android heroine Cutie Honey (1973) and the combining robot team in Getter Robo (1974), created with Ken Ishikawa.

To manage his burgeoning career, Nagai founded his own production company, Dynamic Productions. This allowed him to oversee the numerous manga and anime adaptations of his work. A recurring theme across his diverse bibliography is the fusion of extreme violence with eroticism, often with a sense of dark humor. His stories frequently feature apocalyptic conflicts, transformations, and morally ambiguous protagonists. This is evident not only in Devilman but also in works like Violence Jack, a post-apocalyptic sequel set in the same universe.

The body of work he created in this era has been adapted and reimagined countless times across film, television, and original video animation. For example, the 2000 OVA Amon: The Apocalypse of Devilman serves as an alternate retelling of the climax of the original Devilman story. The 1991 OVA series Anime V Comic Rentaman included segments adapting his crime-comedy manga The Abashiri Family. His 1978 manga Black Lion was adapted into an OVA in 1992. Additionally, his original concept for the 1989 television series Bio Armor Ryger, which features a young boy transforming into a bio-mechanical warrior, demonstrates his continued influence in the mecha and transformation genre well into the late 1980s. The series Chōnōryoku Shōjo Barabanba is also credited to him as an original work.

Go Nagai's industry significance is monumental. He is credited with inventing the super robot genre with Mazinger Z and pioneering erotic comedy in manga with Harenchi Gakuen. His work on Devilman has been cited as a primary influence by countless artists and writers for its grim, apocalyptic storytelling. Despite facing severe criticism early in his career, he persisted in pushing creative boundaries, earning a reputation as a visionary. In 2005, he became a professor of character design at the Osaka University of Arts, and in 2009, he was appointed to the nominating committee for the Tezuka Osamu Cultural Prize, cementing his legacy as one of the most important and innovative creators in the history of Japanese popular culture.