Showa Shell Sekiyu K.K. was established on January 1, 1985, by a merger of equals between Showa Oil Co., Ltd. and Shell Sekiyu K.K. The former was originally established on August 1, 1942, by consolidation amongst three companies: Hayama Oil, Asahi Oil and Niitsu Oil. In April 1949, Showa Oil Co., Ltd. received authorization from Japanese government as an oil distributor and made a return to the business after a respite in the World War II. In June 1949, Showa Oil concluded an agreement with Royal Dutch Shell Group for crude oil import and technical know-how exchange. This relationship was further strengthened in the form of equity participation to Showa Sekiyu K.K. by Royal Dutch Shell Group in June 1951.
Shell Sekiyu K.K. started its history in Yokohama in early Meiji era (around 1876) as an entity called Samuel Company, which was the precursor of Shell Group in later years. On April 11, 1900, it spun out its petroleum business section and named it as Rising Sun Petroleum Company to handle petroleum import and sales. After ceasing operations for several years around the World War II, it resumed operations in 1949 when Japanese government determined the privatization of petroleum distribution sector. Thus, the two companies had a very close relationship both financially and operationally even before the merger in 1985. In December 2016, Royal Dutch Shell Group withdrew 31.3% of Showa Shell equities out of 35% that it used to hold.
