Brad is a bit of an alcoholic. When his martial arts instructor sends him on a quest to find a type of wine known as "Genra," it would seem to be the start of a path to enlightenment that might help him conquer his drinking problem.
The guy spends years wandering around looking for the stuff and literally just wanders into the Dead or Alive tournament. He doesn't go looking to fight, and he sure as hell doesn't seem to care what will happen to him, all he knows is that he has to find that damn wine. He's the ultimate personification of someone who after last orders at the bar are called, is still looking for the after party.
During the tournament, he doesn't stop drinking. On the contrary, liquor pretty much fuels his combat style. He eventually leaves the tournament to continue his booze quest, but after another year passes with no luck (and presumably more Heinekens than you could load into the back of a VW van), he shows up at the next tournament, too.
Brad does eventually discover the wine. When he drinks it, however, it sends him into what basically amounts to an acid trip. So this "Genra" that was supposed to curb his alcohol problem ends up showing him another way to get lit, which kinda makes him the chillest sensei ever.