Much of Reiko's past remains a mystery, but she is known to have been involved with gangs. Apparently she got in by performing 'favours' for them and once in she took up bodybuilding, more that doubling her original weight in muscle.

She also chose to have her head shaved to fit in more with the thug culture. After showing her vicious, ruthless fighting style during one rumble she was made an enforcer, eliminating those who went against the gang. It's not known why, but somehow Reiko had severed ties with the gang. Today she takes to fighting tournaments in order to work off the aggression she has, and takes part in other hobbies such as basketball and illegal street racing.

Reiko is an undisciplined thug, no two ways about it. Her moves come from playing wrestling video games and picking up what she liked from them. She has collected an assortment of tattoos, mostly dragons, and as stupid an idea as she thinks it is she believes to have inherited the power of the dragon.

As strong as she is though, she is also somewhat slow, and spends a large amount of her time sleeping. She is also surprisingly athletic. Having no morals or qualms about killing, Reiko does however show hints of decency. She intended to kill Vega at one terrorist attack before sparing his life upon being asked to. Her hobby in street racing usually means she steals a car, but the flip side is she returns it with a full tank of gas as payment for the loan. When she decides to relax Reiko takes to video games, looking for what she can add to her repertoire.