The game was confirmed as a canonical installment in the Metal Gear series the E3 2009 Sony Press Conference, and will be written, directed, and produced by Hideo Kojima. Set in 1974, ten years after the events of Metal Gear Solid 3: Snake Eater and four years after Metal Gear Solid: Portable Ops. The game is set in Costa Rica, with Big Boss as the central character once more. When an unknown military force invades Costa Rica, the nation must rely on Militaires Sans Frontières, the mercenary army that will eventually give rise to Outer Heaven.
