Complete the game and all simulator battles to gain 263 FRS points. Normally, you have to achieve an S-rank on each mission in Hard mode to reach 300 FRS points. However, there is an easier way to do this. Select one of the easier missions on Hard mode and complete it with a rank of Lower than "S". Then, replay that mission and achieve an S-Rank to receive one FRS point. Continue to replay the mission to earn one FRS point each time you achieve an S-Rank.