It has been ten years since the incident at Raccoon City and the President of the United States has decided to reveal the truth behind what took place. Raccoon City survivor and personal friend of the President, Leon S. Kennedy, arrives to find the President transformed beyond recognition by a bioterrorist attack. Leon is forced to make the hardest decision he has ever made. At the same, Bioterrorism Security Assessment Alliance Member, Chris Redfield arrives in China, itself under threat of a bioterrorist attack. With no country safe from these attacks and the ensuing outbreaks, the entire world's population is united by a common fear that there is no hope left.
Source: IGN
I never beat Resident Evil 5, but this looks to be a massive improvement Leon