In the RBFF guidebook interview, the game's staff were asked about the meaning of the title “Real Bout”? And they responded:

"That was actually the working project title of the original Garou Densetsu. As this development progressed, we wracked our brains trying to come up with a new title for this sequel, and wondered if changing the entire title itself wouldn’t be more interesting. Then someone suggested, “hey, what if we bring back ‘Real Bout’…” So we have a lot of attachment to it, as you might imagine."
Contributed by ProtoSnake