Y'know, outside of Sonic, Sega doesn't really have any superstars. Even his supporting cast are at best minor stars. Sort of the Robin Venturas of video games. The severe drop in name recognition from Sonic the Hedgehog to Jet Set Radio explains why over a quarter of the characters in Sega Superstars Tennis are from the Sonic franchise.
This shot shows Sonic playing against a monkey in a sombrero. They're two of the characters you start with, but by winning the right tournaments you can unlock a chick on rollerblades, a chick in a blue miniskirt and that dwarf from Golden Axe. You remember that game, right? If you had a Genesis back in the day, you might have played it a couple of times when you wanted a break from Sonic and Madden.
I mean, a lot of people have heard of Space Channel 5 and Nights Into Dreams, but how many have actually played them, much less could name a character from them. Yeah, OK, whatever. You knew a guy who knew a guy who had a Master System back in the fifth grade and one time you went to his house and played Alex Kidd in Miracle World. You're sooooo cool.
Honestly, I could have just waited for the new Mario Tennis. They are making one, right? I would have much rather seen Sega make a new Jet Set Radio or Samba de Amigo game (which apparently really is in the works). I'd happily bide my time playing either one of those instead of a watered down tennis sim that doesn't even have Knuckles in it.