Rosemary is a Systems Analyst and Raiden's girlfriend in MGS2
Much of Rose's true past is unknown. Rose is in actuality a Patriot spy. She was ordered by the Patriots to change her appearance to match what Raiden would find attractive in order to be his perfect match. As a result she changed her appearance, clothing style, even the color of her eyes in order to meet the standards of Raiden's psyche profile.
Rose met Raiden in front of Federal Hall two years prior to the Big Shell incident. A group of middle-aged Japanese women came up and asked Rose which building King Kong had climbed in the movie. She replied that it was "probably the Chrysler Building". Raiden overheard the conversation and told them that she was wrong, and that it was the Empire State Building. The two argued about the matter so long that the tourists decided to leave.
Two years after they first met, Raiden was called in for his mission to the Big Shell. Rosemary was also called in as Raiden's support during the mission, under the orders of the Patriots. This upset Raiden, but he soon accepted her being involved in the mission. Rose supported Raiden on his mission by giving him information, saving his progress, and having general conversations. Late in the mission, Raiden was captured by the enemy. Rose contacted him in order to give him her support. It was then that he told Rose of his true past as a child soldier and she revealed to him that she was a Patriots spy and that she was pregnant, before having her communication line cut. Soon after that, unknown to Raiden, Rose was removed from the operation and held by the Patriots.
After Raiden had stopped Arsenal and killed Solidus, Rose was apparently released by (or escaped from) the Patriots. She asked his forgiveness and the pair swore to find their own futures together.
Originally Kojima had intended Rose to be dead at the end of the game, but this idea was scrapped as it would leave the players to wonder whether she even existed at all. Also, Rose was intended to be a blonde, while Raiden was to be brown haired.
