仁義なき戦い
In 1972, he left Nikkatsu and signed with Toei. There he starred in many yakuza films, including Battles Without Honor and Humanity series. Kobayashi was married to popular singer Misora Hibari in 1962, but the marriage ended in divorce two years later in 1964. He remarried actress Kyōko Aoyama in 1967, and she later died in 2020.