Yoshimitsu in Soul Calibur & Tekken

If you're not a fan of either the Tekken or Soul Calibur series, I'd advise you to play those games or read the first and second articles.
Reading about the recent Soul Calibur 4 that is yet to be released, I've always wondered something:
Yoshimitsu is both a character in Soul Calibur II and Tekken 5, two games I've been playing more and more recently. Both of those games are developed by Namco, so you don't wonder why he is in both. He is one of my favorite characters simply due to the silliness of his attacks (he can do Harakiri for no reason, or fly with his sword)
However Soul Calibur II and Tekken 5 take place in two different times. Soul Calibur II takes place in 1591 and Tekken 5 in modern days, around 2000 or so.
Now in the first Soul Calibur, Yoshimitsu loses his arm in battle and replaces it with a prosthetic one. Which can spin and shit and do tricks.
However, in Tekken 5 the Yoshimitsu displayed ALSO appears to have a prosthetic arm, considering it spins and shit and does tricks as well.
What I don't get is, is Yoshimitsu one person that's been living for a long time, or does the Manji clan select certain people to assume the role of a masked ninja called Yoshimitsu over the centuries?

Reading about the recent Soul Calibur 4 that is yet to be released, I've always wondered something:
Yoshimitsu is both a character in Soul Calibur II and Tekken 5, two games I've been playing more and more recently. Both of those games are developed by Namco, so you don't wonder why he is in both. He is one of my favorite characters simply due to the silliness of his attacks (he can do Harakiri for no reason, or fly with his sword)
However Soul Calibur II and Tekken 5 take place in two different times. Soul Calibur II takes place in 1591 and Tekken 5 in modern days, around 2000 or so.
Now in the first Soul Calibur, Yoshimitsu loses his arm in battle and replaces it with a prosthetic one. Which can spin and shit and do tricks.
However, in Tekken 5 the Yoshimitsu displayed ALSO appears to have a prosthetic arm, considering it spins and shit and does tricks as well.
What I don't get is, is Yoshimitsu one person that's been living for a long time, or does the Manji clan select certain people to assume the role of a masked ninja called Yoshimitsu over the centuries?