Play against Master and King
Successfully complete arcade mode using no continues and without losing a round on the normal difficulty setting to play against Master in singles and Master and King in doubles. This can be easily done if the match is set to one round.

Play as Master
Defeat Master in singles in arcade mode to unlock him in arcade and training modes. To do Master's underarm serve, press A + X + Down while at near court, or A + X + Up while at far court.

Play as King
Defeat Master in singles in arcade mode. Then, defeat Master and King in doubles in arcade mode to unlock King in arcade and training modes. Alternatively, complete all 22 trial and 24 training levels in world circuit mode.

Underarm serve
To do an underarm serve, press A + X + Down while at near court, or A + X + Up while at far court.

Sunflower costume
Successfully complete the big wall training level with at least ten seconds left on the timer to unlock costume No. 22.

Tambourine costume
Successfully complete the bull's-eye training level with a score of at least 7000 to unlock costume No. 23.

Camouflage costume
Successfully complete the cannon training level with at least fifteen seconds left on the timer to unlock costume No. 24.

Zebra costume
Successfully complete the smash box training level before the timer turns red to unlock costume No. 25.

Giraffe costume
Successfully complete the drum shooter training level before the timer turns red to unlock costume No. 26.

Fire suit costume
Successfully complete the big ball training level before the timer turns red to unlock costume No. 28.