So awesome that Jason loves Ranma 1/2. One of my favorite animes ever.
I bought it on Blu Rays though and it's unbelievably slow, but the manga was still good!
I don't know when was the last time you read the manga but the anime is super faithful to it so I don't get the whole "it's unbelievably slow".
As many people have mentioned there are more than one Ranma 1/2 fighting game on the SNES. Personally I know of three: Ranma Nibunnoichi - Chougi Ranbu Hen, Ranma Nibunnoichi - Chounai Gekitou Hen and Ranma Nibunnoichi - Hard Battle.
Also he could have played a rom hack or some sort on a cartridge. I remember buying a cartridge of what I thought was "super mario 10(or 15)" but years later I found out it was a reskinned Kaiketsu Yanchamaru 3: Taiketsu! Zouringen. Still I think I played the superior version because... holy shit the enemy(non-boss) design of the original is just X_X
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