The author of the "Barefoot Gen" manga, Keiji Nakazawa, said that 70% of the story is based on true events from his experience of the atomic bombing of Hiroshima.
Inspired by Keiji Nakazawa's story, a group called "Project Gen" was formed. It was a group of students from Japan, USA and Russian that sought to translate the manga series into several languages and distribute them worldwide as an attempt to spread an anti war/nuclear weapons message.
Gen was named after the terms "genki" (vitality of spirit) and "genso" (element), as Keiji Nakazawa wanted him to represent the element of the human spirit.
The film was part of a 1980s cycle of films about atomic bombs and nuclear warfare which had started in 1979 with Síndrome da China (1979). The films included Silkwood, Retrato de uma Coragem (1983), Herança Nuclear (1983), Catástrofe Nuclear (1984), Jogos de Guerra (1983), O Dia Seguinte (1983), Atomic Café (1982), Jogos Fatais (1986), Whoops Apocalypse (1982), Special Bulletin (1983), Segredos Nucleares (1987), Barefoot Gen (Gen Pés Descalços (1983)), Rules of Engagement (1989), Quando o Vento Sopra (1986), Letters from a Dead Man (Cartas de um Homem Morto (1986)), Memoirs of a Survivor (1981) and Reação em Cadeia (1980).