Tennis 2K2

Special rackets
Play in world tour mode. Beat your opponents in stage 3 and higher
without losing a single set. If you win, you will receive a
special racket in all the championship which you won.

Alien Force racket: Finish Alien Force Volley training level 4.
Tank racket: Finish Tank training level 4.
Bull's Eye racket: Finish Bull's Eye Training level 4.
Prize Sniper racket: Finish Prize Sniper Training level 4.

Head i.Radical OS racket: Win 1st place the Head International
Women's Single Tournament in world tour mode without losing.

Head IS18 Chip System racket: Win 1st place the Head International
Men's Doubles Tournament in world tour mode without losing.

Change clothes
Go to the character selection screen, then hold L or R
and select a character.

Unlock King or Queen as playable character:
Beat all the matches without using a single continues.
If you were playing as a male character, you will face King, if you were
playing with a female character, you will face Queen. Beat them,
after they will unlocked.

Unlock King's Court
Play in world tour mode and beat the Queen and the King also in stage 5.
To unlock Stage 5, you have to win the mixed double match in stage 4.