Mario
First Appearance: Donkey Kong (1981)
First Tennis Appearance: Mario's Tennis (1995)
Class: All-Around
To Unlock: Available At Start

Luigi
First Appearance: Mario Bros. (1983)
First Tennis Appearance: Mario's Tennis (1995)
Class: All-Around 
To Unlock: Available At Start

Peach
First Appearance: Super Mario Bros. (1985)
First Tennis Appearance: Mario's Tennis (1995)
Class: Technique
To Unlock: Available At Start

 Daisy
First Appearance: Super Mario Land (1989)
First Tennis Appearance: Mario Tennis (2000)
Class: Technique
To Unlock: Available At Start

 Yoshi
First Appearance: Super Mario World (1990)
First Tennis Appearance: Mario's Tennis (1995)
Class: Speed
To Unlock: Available At Start

Boo
First Appearance: Super Mario Bros. 3 (1988)
First Tennis Appearance: Mario Tennis (2000)
Class: Tricky
To Unlock: Available At Start

Bowser
First Appearance: Super Mario Bros. (1985)
First Tennis Appearance: Mario Tennis (2000)
Class: Power
To Unlock: Available At Start

Bowser Jr.
First Appearance: Super Mario Sunshine (2002)
First Tennis Appearance: Mario Power Tennis (2004)
Class: Tricky
To Unlock: Available At Start

Donkey Kong
First Appearance: Donkey Kong (1981)
First Tennis Appearance: Mario Tennis (2000)
Class: Power
To Unlock: Available At Start

Diddy Kong
First Appearance: Donkey Kong Country (1994)
First Tennis Appearance: Mario Power Tennis (2004)
Class: Speed
To Unlock: Available At Start

Wario
First Appearance: Super Mario Land 2 (1992)
First Tennis Appearance: Mario Tennis (2000)
Class: Power
To Unlock: Available At Start

Waluigi
First Appearance: Mario Tennis (2000)
First Tennis Appearance: Mario Tennis (2000)
Class: Defense
To Unlock: Available At Start

Mii
First Appearance: Wii Sports (2006)
First Tennis Appearance: Mario Tennis Open (2012)
Class: Customizable
To Unlock: Available At Start

Dry Bowser
First Appearance: New Super Mario Bros. (2006)
First Tennis Appearance: Mario Tennis Open (2012)
Class: Defense
To Unlock: Clear Ink Showdown 

Baby Mario
First Appearance: Super Mario World 2: Yoshi's Island (1995)
First Tennis Appearance: Mario Tennis (2000)
Class: Speed
To Unlock: Clear Super Mario Tennis Special Game

Baby Peach
First Appearance: Mario & Luigi: Partners in Time (2005)
First Tennis Appearance: Mario Tennis Open (2012)
Class: Tricky
To Unlock: Clear Ring Shot Special Game

Luma
First Appearance: Super Mario Galaxy (2007)
First Tennis Appearance: Mario Tennis Open (2012)
Class: Technique
To Unlock: Clear Galaxy Rally

Red Yoshi
First Appearance: 
First Tennis Appearance: Mario Tennis Open (2012)
Class: 
To Unlock: QR Code

Blue Yoshi
First Appearance: Super Mario World 2: Yoshi's Island (1995)
First Tennis Appearance: Mario Tennis Open (2012)
Class: Speed
To Unlock: QR Code

Light-Blue Yoshi
First Appearance: 
First Tennis Appearance: Mario Tennis Open (2012)
Class: 
To Unlock: QR Code

Yellow Yoshi
First Appearance: 
First Tennis Appearance: Mario Tennis Open (2012)
Class: 
To Unlock: QR Code

Pink Yoshi
First Appearance: 
First Tennis Appearance: Mario Tennis Open (2012)
Class: 
To Unlock: QR Code

White Yoshi
First Appearance: 
First Tennis Appearance: Mario Tennis Open (2012)
Class: 
To Unlock: QR Code

Black Yoshi
First Appearance: 
First Tennis Appearance: Mario Tennis Open (2012)
Class: 
To Unlock: QR Code