Kengo Not much is known about Kengo other then the fact that he has an Odd Genetic Disorder in his eyes. Which is unique to him , no one has figured out why his eyes are deformed, mainly because everyone who has seen them , has died of unknown causes.
Kengo was around before the era of ninja villages , This is theorized because of his rambling of " Two Rivals of legend fighting, one with a body of wood (Possibly Hashirama Senju), and one with a spirit of fire (Possibly Madara Uchiha)
Shortly after the 9 Tailed Demon fox was sealed within the body of a young child , Kengo's house hidden in the hills mysteriously burned down. It was found 16 years later , with a photograph of what appears to be Madara Uchiha , Engraved on the frame "For my l--------- , peace will finnaly be real"