Kōhan Kawauchi, also known as Yasunori Kawauchi, was a Japanese screenwriter and creator born on February 26, 1920, in Hakodate, Hokkaido. He passed away on April 6, 2008. Kawauchi is recognized as a pioneering figure in the tokusatsu genre, having created the first Japanese TV superhero series, Moonlight Mask, which aired in 1958.

Kawauchi created numerous tokusatsu series throughout his career. Among his notable creations are Seven Color Mask from 1959, Messenger of Allah from 1960, and Warrior of Love Rainbowman from 1972. The original Rainbowman series was a live-action tokusatsu production, the first superhero TV series produced by Toho Company Ltd. Kawauchi also wrote the screenplay for Seijun Suzuki's 1966 yakuza film, Tokyo Drifter.

The 1972 tokusatsu series Warrior of Love Rainbowman, created by Kawauchi, was later adapted into an anime television series. This 22-episode anime remake, also titled Warrior of Love Rainbowman, aired from October 1982 to March 1983. Kawauchi is also credited with the original anime series Mock & Sweet, which aired from 1986 to 1987. For this series, he contributed as a writer under his birth name, Yasunori Kawauchi.

Kawauchi also wrote lyrics for theme songs related to his creations, including the opening and closing songs for the 1972 Rainbowman series. In 1959, he converted to Islam, a personal decision that later influenced the creation of his 1960 series Messenger of Allah.

His work has had a lasting impact on Japanese popular culture. The original Warrior of Love Rainbowman is considered to have been an inspiration for Go Nagai's famous manga and anime series, Cutie Honey.