A former police officer and current member of the TAC, Ryoko generally serves as the mature, calm voice of reason within the group, though she has a playful side. Not much about her past is revealed, nor the reasons why she joined or was transferred to the top-secret organisation. Her abilities are generally within normal human parameters, though she is well-trained in detective and law enrforcement work, and is a crack shot with a pistol.
She appears to have an infatuation with Director Kunikida, though she is either too shy or too professional to come out and say so.