What is this Yama Sakura Exercise anyway?

Yama Sakura

Yama Sakura (YAMA SAKURA means Mountain Cherry Blossom) is an annual, bilateral command post exercise that simulates Japanese-US military operations required to defend Japan. Yama Sakura is a computer simulated command post exercise designed to strengthen military operations and ties between the U.S. Army. and the Japan Ground Self-Defense Force. Yama Sakura is a yearly command post exercise between I Corps and the JGSDF sponsored by USARJ and the Japanese Ground Staff office. It is I Corps' largest and most important exercise in Japan. Every year, one of the five regional Japan Ground Self-Defense Force (JGSDF) Armies is joined by US Army I Corps to conduct the exercise in Japan and the US.
Since their inception in 1982, these exercises have focused on the development and refinement of the Japan Self-Defense Forces (JSDF) and U.S. Army Japan (USARJ) efforts in the areas of bilateral planning, coordination, and interoperability through training. The first YAMA SAKURA was held in 1982 with a total of 570 US soldiers participating.
Although each annual event has grown in scope, magnitude and complexity, the exercise’s mission has remained unchanged from its original mission: "To conduct a joint/bilateral command post exercise (CPX) with JSDF and U.S. forces to train for the bilateral defense of Japan." YAMA SAKURA exercises have had four mission objectives: 1) To train U.S. ground forces for deployment to Japan, 2) Provide JSDF maximum exposure to U.S. warfighting doctrine, 3) Exercise JSDF capabilities to defend Japan, and 4) prepare USARJ/9th Theater Army Area Command (TAACOM) for its wartime mission.

source: http://www.globalsecurity.org/