The PS secret chars known to this day are:

Gon, Anna and Dr.Boskonovitch.

The arcade secret characters are released when beating the game/or time release:
Each time you finish the game, a character is released. If you don't, the game will release a character every 1 or 2 hours.
Release order: Kuma, Julia, Gunjack, Mokujin, Anna, Bryan, Heihachi, Ogre, True Ogre.


Gon

The small dinosaure is a comic star in Japan.
Here, Gon (in his 2P costume) is with DR.Boskonovitch in Tekken Ball mode...
Note: getting Gon will also release his "beach" secret stage.
Unlock method: Beat him at Tekken Ball.






Anna

She is different from Nina, and so she is not the Anna of the Arcade version. She is now a separate character.
Unlock method: Beat the game with 5 chars (normal "not standard" char).






Dr.Boskonovitch

He is the scientist who created/upgraded the jack series (to make them war machines), and replaced Yoshimitsu's hand, among other wonderfull things. Why the heck is he fighting (fighting or falling? :) now, you might ask... Well, I've been asking the same question for weeks now... ^_^.
Here you can see both costumes in training mode.
Note: getting the Dr. will also release his "underground cave" secret stage.
Unlock method: Finish force mode 4 times.



Secret costumes

It has been confirmed; this is just a secret costume for gunjack. For the info about the secret costumes, go to the codes page.