Tenchi is 16 at the start of OVA 1 he turns 17 shortly into it and around ova 3 he should turn 18 hence why they are getting ready to tell him about how kiyone died.
Washu is as old as time but her current form is around almost exactly 20,000 years old.
Ryoko's Age is unknown but... she is over 700 years old and was made after naja died so she's at least under 5700 and she still looks 19 ish or 17ish according to hasegawa.
Naja was about 14302 years old when she went missing
Seto appeared to be 6 when she was found around 3708 bc ... but we know she was just naja... if she was six though she would be around 5707 around ova 3.
Yosho: around 724 in ova 3
Airi: around 727 in ova 3
Seina: 15 at the start of ova 3
17 durring the renza ark
17 durring the renza ark
Sasami and Ayeka were born 11 years apart they were age 8 and 19
when they left jurai and entered stasis and were in stasis for 695 years.
so technically 703 and 716 at the beginning of ova 1 and they both age a year by ova 3
Mihoshi: 25?
Funaho: 747
Misaki:717
Azusa:754
Misao: 24
Mashisu: 23
Kiriko and Noike: 20
Tennyo: 80 as of ova 3
Kiyone was 428 when she died
on aging in general an except from gxp 4 is most appropriate
"oh i see... so you were doing a search on Washu Hakubi."
"Today, after seeing that scenery .... I am a little interested in the subject ... ...."
"Well living in the academy you're sure to hear all sorts of thing about it's most famous citizen, but it really won't do much good to do a search on her. She was here for over is history for over 15,000 years anyway"
"15,000 years?!"
"well she only went missing five thousand years ago .... so there's about 20,000 years of stuff on here total."
Seina looked amazed at the Erma's sense of time, on earth that was an archeological amount of time.
"Is he really a human, that person?"
"Oh, even ordinary people can live for about two thousand years now, and with modern technology, you can live almost infinitely if you undergo special treatments like you did Seina. With your Bio-Enhancement, You should be around for much longer than 2,000 years "
" two thousand ..."
The unrealistic figure stunned seina.
( two thousand is almost the same amount of time as the Christian calendar* Kiriko said that it would't be possible to live a normal life, it is this kind of thing she meant?) *also evidence that this is in the 90's and not modern times.
it was then that Seina finaly felt that he was no longer a normal Earthling for the first time.
"are you freaked out by that?"
"Eh ... yeah ... a little."
"well ms.Kiriko can probably be a counselor to you on this then i can, since she is also from earth, but I've never really thought much of it since everyone around me has always had a similar life span. "
"Well, i guess that makes sense, but I still think Washu's 20,000 year age isn't normal ..."
"It is recently that lifespan technology came out in general but she was a philosopher when the academy had its best scientist. And I've heard that even heard that there are some students of hers that are still around due to the enhancements that were available to them with the private medical technology they had at the time. ... ... ... ... "