Noa is a chimpanzee. Raka is an orangutan. Mae is a female human with blue eyes. Noa has green eyes, and Raka has brown. They can speak fluently and get their intelligence and green eyes from the ALZ-113, a cure for Alzheimer's, which killed 99% of humans 300 years ago, and mutated so all human carriers who didn't die became mute. Mae can speak, though, which is rare. Raka is the last member of the Order of Caesar, and admires Caesar, a chimp, who lived 300 years ago, and was king of the apes.