Born in Yoichi, 1960. Lives in Sapporo. Since 1970, Sakai has photographed Hokkaido in various series. His major photo series include Natsu no Shoshitsuten (lit. Vanishing Point in Summer) (1979), as well as Gukei/Sightseeing, Sokoni Tatsumono (lit. Standing There) and Hokkaido no Tabi (lit. Journey in Hokkaido) (these began in the 1990s). He was involved in planning and editing at the SIAF2014 collaboration program, Hyoshutsusuru Shashin, Hokkaido (lit. Exposed Photos, Hokkaido) (organized by the NPO Network of Photographers Promoting Hokkaido) in 2014. He won the Special Photographer Award of the 30th Higashikawa Awards in 2014, and the 68th Hokkaido Cultural Encouragement Prize in 2016.