In the prototype version of the game, Raidou is given an end card sequence, hinting that he would have been unlockable in the final version.

"Is this the end? ...
I looked down at my opponent who fell at my feet and muttered the thunder track. It's been a long time since you came out to be chasing a village like this or the one Kirigen Tenjinryu. Since then, the thunder road has only sought power for appetite. Fight against all the fighters, made his technique his own. I was asked to be a member of the tournament because I had a feeling that I might be able to meet the hunger for mosquitoes. However, it seems to be useless. The thunder road called a storm and disappeared into the fog..."

Bayman's codename "Gatsby" from the game's early development is based on the American novel The Great Gatsby.

The very first character developed for the game was a fighter codenamed "Kelly", who was originally cut from the final roster for being incomplete compared to later characters. However, since the team needed one more fighter, they decided to go back and develop a more complete version of Kelly. That character became the final version of Zack.