A girl who simply does not have any time for men, and a boy whose ambitions are larger than his huge ego. Riza Hawkeye, and Roy Mustang. What are two people living in the same house supposed to do when the other is so different? Fall in love, of course. After growing closer, Riza and Roy proceed to join the military together. They fight side by side, yet also against each other. They protect each other from enemies, yet also from the other. This is the story of how RoyAi came to be.