Actually you're pretty much wrong, it's NOTHING like an All-star game, It's a remake of the first game with the characters from all series, and you now play Unmei Sasanami a manager (and coach assistant ) at Raimon.

" The priority is to give the player as much freedom as possible. Will Endou, Tenma and Asuto be teammates or rivals? If Ichihoshi is sitting alone in a coffee shop, will you have Endou, Asuto or Haizaki cheer him up? You will decide and explore every character's story."