In the OVA series, Ryoko spent 700 years trapped in a cave after her attack on Jurai, but had been created some 4,300 years previous to this event, shortly before Washu was imprisoned by Kagato, hence her chronological age of over 5,000 years (though she has mentioned her age as 2,000, this has been explained by saying she quotes her age in "galactic standard years" to make herself sound younger). In the first TV series, her chronological age matches Ayeka's (as we see her as a child meeting Princess Ayeka, also as a child).

Ryoko is in possession of incredible powers. She is capable of flight, dematerialisation, passing through matter, demon summoning and can use explosive fireballs and a blade of energy as weapons. She has also displayed other capabilities, such as the manipulation of matter (eg. the giant stone Ryoko in OVA #6), fast healing (eg. replacing her severed hand in OVA #1) and creating temporary duplicates of herself. However, her OVA self has a number of known limitations; she lacks many physical sensations including taste, and it takes copious amounts of alcohol to make her intoxicated, hence her penchant for sake! In the first movie, it is mentioned that Ryoko's teleportation powers are limited to carrying her only between places she has seen or been to before.

In the OVA series, it is explained that Washu created Ryoko by combining her own ova (egg cells) with shape-shifting creatures called The Mass (Masu, in the Japanese version). No such link between Ryoko and Washu is evident in either TV series.

As mentioned in OVA #4, Ryoko's name means "spirit caller".