A spinner is a petite woman. Denoted as a joke, whereby the woman is so small she is able to be mounted and spun in a circle on an erect penis. Related questions (More answers below)

Spinner  (Adjective  Slang) Used among some men to describe an extremely petite young woman, usually with a lot of sex appeal  the term is thought to reference the small stature and weight of the woman; (IE she is so petite she could be spun around while riding the man during sex).

The quote has been translated to "Fun is infinite - Sega Enterprises - Signed: Majin" Majin is Japanese for devil, so it says "Fun is infinite with the devil." Sega apologized for this saying they would never do it again, and it was simply a joke to the JP/EUP players.

Pre-Super Genesis Wave. In the Sonic The Hedgehog and Sonic Universe comics, their relationship is similar to the games. The comics started as a promotion for the animated series, so Sonic has a relationship with Sally Acorn from the beginning.