If you are playing via the emulator (PSP environment) or a PS1 original:

You can try the following options:

If you prefer to unlock them yourself, follow these milestones in Arcade Mode

is a popular way to bypass the lengthy grind of unlocking the game's iconic 21-character roster. While the game is technically a PS1 Classic , it is widely played on the via official PlayStation Store purchases or through homebrew emulation. The Value of an Unlocked Save Unlocking everything manually in requires clearing Arcade Mode

An “All Characters Unlocked” Tekken 3 PS1 save file for Vita or emulators offers a fast way to access the full roster for practice, content creation, or casual play. Use region-matched files from trusted sources, back up originals, and be aware of legal and compatibility concerns. For players who prefer not to use external saves, in-game unlocking remains the safest and fully legitimate path.

If you have a PS3, copy the virtual memory card save to it first, then connect your Vita and use Content Manager