These are all of the Guest characters you can encounter in this game. To unlock them, you must beat them in their respective sport after earning a medal in the Tournament Mode. Note that these characters aren't playable in any other sports.

Character	How to Unlock
Diddy Kong	Beat the Level 1 Rugby Sevens Tournament.
Dry Bowser	Beat the Level 2 Javelin Event.
Espio	Beat the Level 2 Triple Jump Event.
Jet	Beat the Level 1 Football Event.
Larry	Beat the Level 2 Equestrian Event.
Nabbit	Beat the Level 2 100 m Event.
Rosalina	Beat the Level 1 Rhythmic Gymnastics.
Rouge	Beat the Level 1 Beach Volleyball Event.
Sticks	Beat the Level 2 Archery Event.
Toad	Beat the Level 2 4x100m Relay Event.
Wave	Beat the Level 1 BMX Event.
Wendy	Beat the Level 2 Swimming Event.
Zavok	Beat the Level 1 Boxing Event.
Zazz	Beat the Level 1 Table Tennis Event.