Complex sentence: He later traveled to Japan where he was a professional wrestler and learned the ins and outs of working fake fights the Pro Wrestling Fujiwara Gumi (a shoot-style professional wrestling organization) champion for close to three years.
Split into simpler sentences: He later traveled to Japan where he was a professional wrestler and learned the ins and outs of the sport. He was the Pro Wrestling Fujiwara Gumi (a shoot-style professional wrestling organization) champion for close to three years.