Born in 1973 in Tottori Prefecture, Adachi Shin graduated from the Japan Academy of Moving Images, a film school founded in Yokohama in 1975 by director Imamura Shohei. Adachi served as an assistant director to Somai Shinji and started writing scripts. His first feature scriptwriting credit was for the 2004 pro wrestling comedy Mask de 41. His breakthrough was the script for the 2014 boxing drama 100 Yen Love, which won him a Japan Academy Award. In 2016 Adachi made his directorial debut with the semi-autobiographical teen comedy 14 That Night.