In all series she is a space pirate, although the manner of her being one is different from series to series - in the OVA she is one at Kagato's behest and under his control, raiding Jurai and inadvertently being the cause of Sasami's near-fatal accident. In Tenchi Universe it seems to be her own choice and a life she has come to love - although we do not discover who her family are or how she got into that life in the first place. And in Tenchi in Tokyo, she seems to be driven into it by greed, bitterness and a desire to fight and cause mayhem.

Ryoko's age in the OVA is somewhere around 5000 Earth Years, though she has spent much of that imprisoned in the cave. Her age is not given in the Universe series it's likely that it's quite a bit older than Tenchi's own. (It all depends on which years you calculate by, obviously!). Ayeka does once refer to her as a seven hundred year old mummy woman (in her Karaoke song in the episode No Need For Hiding) but that is probably simple confusion with the OVA backstory on the part of the writers. (Or perhaps not...who knows?)

In Tenchi Universe, Ryoko's backstory is a couple of snippet memories recalled by Ayeka and Ryoko at various points. One is in a field full of flowers, and another at a carnival on a nearby planet to Jurai. The girls remember the events quite differently, but I suspect there is a great amount of truth in both tellings - and that each has just exaggerated the negativity of the other to make their story sound more sympathetic to themselves. If you balance it out, you can easily assume that Ryoko and Ayeka have some kind of 'past' that dates back to childhood (and also puts them at about the same age, too).

The only other clue we have to her origins in Tenchi Universe are a gaggle of unpleasant looking characters discussing her in Nagi's hearing in episode ten, "No Need For An Arch Rival." This is as close as we get to a real background view of Ryoko's life...one of the men comments on her apparently settling down with a man somewhere, which draws mirth from the others and the suggestion is from their conversation that her life as a space pirate was quite different - that she fitted in as 'one of the guys'.

Nagi is also a part of her past, of course. As Ryoko relates, "We have faced each other many times. Of everyone she has hunted down, nobody has ever survived. Nobody...except for me." The black and white flashback of Ryoko's memory gives us what is presumably their last encounter and her apprehension about the conflict ahead indicates that this is the one person Ryoko is not 100% sure she can take down. It seems likely that she has suffered injury many times at Nagi's hand, and since Nagi knows how to disable her orange light sword with her whip, it's clear they know each other's strengths and weaknesses very well.

The one other clue occurs in the episode "No Need For Hunger", when Ryoko robs the Bank of Jurai. Aside from the obvious things - drinking, gorging, gambling, stealing - that probably made up her life before she fell on the Earth, there is an interesting image of Ryoko given in this episode. She is dressed quite differently from how we ever see her in the series, and the getup of the 'Space Pirate' is something she is not even wearing when she falls to the Earth. The fact she wasn't wearing this during the conflict with Mihoshi almost suggests something had happened to make her give up her active pirate's life. We don't know what and this is a lot of reaching. But even though sometimes she does steal and do other pirateish things, she is in no hurry to leave the Planet Earth and get back to her life of crime. There surely must be a reason why...can it really be only love for Tenchi keeping her there?

In Tenchi In Tokyo/Shin Tenchi Muyo, Ryoko has perhaps the harshest background of all three series. She is no longer dressed in what you might think of has her 'traditional' outfits from the OVA and TV series 1 and nor does she have Ryo Ohki (I have to admit a small annoyance at the fact that Sasami has become a definite cabbit thief in this series!!). She and Washu are no longer linked in the same way that they are in the OVA or even potentially in Universe, but instead Washu is her sidekick and they crash to the Earth together in search of a power source. Ryoko is presented as a dangerous, ambitious pirate who is willing to take more or less any risk to win and who has encountered the wrath of Ayeka and the Galaxy Police by stealing the Jurai Powerstone. Whatever that might be...

It's been debated/discussed exactly how vicious a Space Pirate Ryoko actually is across the various stages/series/canons that exist. In the OVA, she is more or less exempt from blame for her crimes since they were under the influence of Kagato's spell. In Tenchi Universe, we don't discover much about her crimes, only that they are many (and that she adds to them by stealing from the Bank of Jurai when they are on the run from the Jurai authorities and the Galaxy Police). In Tenchi in Tokyo, she is probably the harshest kind of pirate of all...and yet she inspires the loyalty of her followers because she brings them great success. There is nothing to suggest Ryoko kills anyone in the OVA or Universe. However, in Tenchi in Tokyo, she definitely does kill Hotsuma (although he is trying to kill her at the same time). And there is the little matter of the Galaxy Police ships she shot down - although I find it hard to believe that she slaughtered people in that attack, because otherwise the Galaxy Police devotee Kiyone would certainly not have wanted to sit down to tea with her ever again. Murder is never levelled at her name, so I think we must assume those crafts were piloted either automatically, or that somehow their crews escaped the force of Ryoko's blasts. We'll never know for sure, of course...but turning her into a mass murderer when she's on the good guy's side is probably not very likely - if it was, she'd have actually slain more people than the series villain, Yugi!

RYOKO: SPECULATION
I've stuck this in down the bottom on it's own, because this is my own thinking rather than something concrete put out by the series. It's my belief that Ryoko is at least part Juraian (as anyone who's read my fanfiction will testify to, whether they agree with me or not). So here is the evidence. Firstly, in the OVA, the gem magic she uses is supposed to be some form of Jurai magic, though it's source is undefined. In Tenchi in Tokyo, Ryoko uses the Jurai Powerstone to battle against Ayeka - could she really use this power if she wasn't at least partially a Juraian herself? And then, in Universe, there are startling similarities between her powers and those that Kagato possesses - including teleportation, flight and the sword she can manifest. We also have shared memories between her and Ayeka - what would a small girl be doing on a Jurai planet anyway? She could not have got there on her own, unless it was where she was living! And there is the little matter of the fact she knows how to get to the Jurai Royal Palace - AND is intimately acquainted with their inner security systems! Also, if you're so inclined, it's worth taking a second look at the manner in which she attacks Kagato. Her blast of energy - which is normally a bolt or a ball in appearance - has suddenly developed three adjoining sides. Could they be a distant hark back to the Light Hawk Wings of the OVA? (More connections to Kagato can be found in his bio!)

She can also call up a forcefield in this series, which is something Washu does on occasion - indicating she might well be Washu's daughter, also. This is all wild speculation, of course - but you have to admit, it carries a certain resonance!