It's the year 20XX. After Dr. Wily's plan to use evil energy from outer space was foiled by Mega Man (see Mega Man 8), peace has returned once more. However, that peace was only temporary, because a mysterious new robot named King started an uprising against humans that mistreat robots. Furthermore, he also took over Dr. Wily's Castle, kicking out Dr. Wily and his creation, Bass, in the process. Now it is time for Mega Man and Bass to team up to take down a greater foe. Will they successfully defeat King's army of robot masters? And will they be able to find out the secret behind King?
