Kei Kumai (熊井 啓, Kumai Kei, June 1, 1930 – May 23, 2007) was a Japanese film director from Azumino, Nagano prefecture. After his studies in literature at Shinshu University, he began work as a director's assistant. He won the Directors Guild of Japan New Directors Award for his first film, , in 1965. His 1972 film Shinobu Kawa was entered into the 8th Moscow International Film Festival. His 1974 film Rise, Fair Sun was entered into the 24th Berlin International Film Festival.