Founded in 1724, Oujiman is located in Tsuruoka City, Yamagata Prefecture, Japan, and is named after the "Sato Jinzaemon Shuzojo" brewery. The brewery has primarily focused on sales within Japan, but in 2018, the president expanded its sales reach to include regions like Hong Kong and Macau in Greater China.
Oujiman insists on using 100% Yamagata Prefecture rice, primarily brewing junmai-grade sake. In 2019, a young toji (master brewer) named Abe Ryuya joined Aobayama Jiman, earning the distinction of being one of the youngest toji in Yamagata. He has injected new energy into the brewery, bringing in fresh ideas and creating trendy, innovative styles of sake.