American Showa, Inc. was established in December of 1979 as a sales office located in Chicago, Illinois. In January, 1981 Showa moved its office to Los Angeles, California .The new focus was to provide technical support and service to American Honda Motor and American Suzuki Motor. It also supported Team Andretti Green IRL Support via Honda Motor Company. In 1985, the L.A, Technical Support business became a division of the newly created American Showa, Inc.

In 2001, American Showa Technical Support moved to its current location at 1235 Graphite Drive, Corona, California. Operations include motorcycle test support and racing technical service for motocross and off road racing.

In January 2021, SHOWA and Hitachi completed the merger and the Technical Support office is now a part of Hitachi Astemo.