Shōnen Jump Plus digital manga magazine has debuted a new spin-off manga that re-imagines Yamcha as the main hero in Dragon Ball and Dragon Ball Z. In it a teenage boy dies tripping down some stairs, however he quickly wakes up as Yamcha during the early part of the Dragon Ball series.
Being caught up in the events of the DBZ universe he trains to become the strongest of all the heroes. Knowledge is power and he exploits this to out due his fellow Z warriors.
You can see it (though probably not read it since it’s in Japanese) here.