Metal Gear Solid 2: Sons of Liberty
Throughout Metal Gear Solid 2, Rose acts as part of Raiden's support team along with Solid Snake and Colonel Campbell, she is also Raiden's girlfriend. She continually harasses Raiden by asking him if he "knows what day it is tomorrow", and other general small talk. Rose shows signs of jealousy when Raiden is holding hands with Emma Emmerich. Eventually, when Rose accused him of never opening up to her, Raiden told her of his days as a child soldier in Liberia. In response, Rose confesses that she is a Patriot agent, and everything about her was falsified to make Raiden attracted to her, even the color of her hair and eyes. She also told him that she was pregnant with his child. Soon after this, unbeknownst to Raiden, Rose and Campbell's line to Raiden was cut by the Patriots, and replaced by an AI.
After Raiden had killed Solidus Snake and Emma had shutdown Arsenal Gear, Rose either was released by or escaped The Patriots. After being inspired by Snake, Raiden forgave Rose (who had now actually fallen in love with him), and they swore to each other that they would start a new life with each other. It was revealed that that special day, which was April 30th, was the day when the two of them first met.
Metal Gear Solid 4: Guns of the Patriots
After the events of Metal Gear Solid 2, Raiden suffered from a severe caste of Post Traumatic Stress Disorder and he took to drinking heavily. It was during this time that he rescued Olga's daughter Sunny from The Patriots, and Rose told him that she had had a miscarriage. One night, he left, and never came back.
Rose then married Colonel Campbell, which caused her relationship with Raiden to disintigrate further, this also caused the Colonel's already fragile relationship with his daughter Meryl to also disintigrate. The Colonel then decided that her talents as a pyschological counselor could be put to use telling Snake how to handle stress on the battlefield.
At the end of the game, Rose and a little boy with Raiden's fair hair and complexion come to visit Raiden, who has been given a more natural looking artificial body, in the hospital. Raiden, thinking that "the kid" is Campbell's, refuses to look at the pair. It is then that Rose reveals the marriage was a sham, which only served to protect Rose and their son. Rose later told Raiden that the Colonel had sacrificed everything to ensure their safety. Raiden again forgives Rose, and when he tells her that he feels like "this is a scene from Beauty and the Beast, she replies by saying "No, you're my husband".