Stories tell of a legendary soldier who, with Metal Gear in his command, had once waged war against the world. His name is Naked Snake, a.k.a. Big Boss. Now, in response to a world hungry for answers, the truth behind this legend will finally be told. The era is the 1970’s. Big Boss had stationed his "Soldiers without Borders" in Columbia, South America, where he was approached by a visitor from Costa Rica "a Nation without a Military". In the wake of the Cuban Missile Crisis, as Latin America became a key to maintaining the power balance between East and West, Costa Rica had miraculously managed to maintain its peace and neutrality. However, in various regions of the country, a mysterious armed force seemed to be engaging in suspicious activities. Now, to preserve peace in this nation without a military, the "Soldiers without Borders" move into action. In time, they would come to be known as the founders of "Outer Heaven." Forge a new path and live the legend with "Metal Gear Solid Peace Walker", the first official "Hideo Kojima Game" on the PSP system!