Defeating the dragon Ranma 1/2 & Street Fighter crossover
After the failed weeding, Ranma meets Ryu, challenges him to a fight and loses. After that Ranma disappears, one year later, Ranma lives as a street fighter in USA, while both the Tendos and Cologne want him to go back to Nerima.
You do remember how much of a sore loser Ranma is? How he was trained to be the best? How he seems to care more about winning than even about the curse? So yes, I do think Ranma would just leave everything behind to get strong and become the best. Let's face it, martial arts is the only good thing he is good at, his father made sure of that.
Yes, almost cannon Ranma, no extra powers. Well maybe he has improved some of his techniques over a year, but while Ranma never used ki attacks much, after facing Ryu you would want a bad-ass ki attack, right?
I think he would cut off his pigtail, and dye his hair black so even if he turns into a girl he would be less noticeable. After all an asian with short black hair, be it male or female, is less noticeable than a pigtailed redhead asian. There is the blue eyes, but is not like blue eyes are that rare in America, and using glasses or contact during a fight is a bad idea, unless they are sport glasses, but even then, they are a risk. He would also the clothes he usually wears.
And where most of the action would be? Well, I don't know if telling some of Ranma world tour first, or start the fanfic when Ranma arrives to Metro City for an Underground Street Fighter Tournament. I picked Metro City because Street Fighter has recycled some characters from the Final Fight series, so Metro City exists in Street Fighter canon. I will also ignore the events of Final Fight 3 because the city was destroyed.