Alternate costumes
At the character selection screen, hold L1 or R1 and select a character.

Play as King or Queen
Win all matches without using any continues. If using a male character, you will face King. Otherwise, you will face Queen. Defeat them to unlock them as playable characters.

Special rackets
In the world tour mode, defeat opponents in level 3 and higher without losing a set. If you win a straight set you will get a special racket in every championship that you won.

King's Court
Defeat King and Queen (mixed double) level 5 in world tour mode to unlock King's Court. This level 5 will only be available if you won the mixed double match in level 4. Both matches will be in December.