Hiroaki Sato is a Japanese professional wrestler and mixed martial artist, better known by the ring name Hikaru Sato . Sato started his MMA career in February 2000, fighting for Pancrase Hybrid Wrestling. During the next eight years, Sato fought, on average, five times a year, compiling a record of 18 wins, 19 losses and four draws, which included fights against the likes of Keiichiro Yamamiya, Nathan Marquardt, Ryo Chonan and Yushin Okami. In May 2008, Sato transitioned into the world of professional wrestling, when he was signed by the Dramatic Dream Team (DDT) promotion. He has since had ten MMA fights. In November 2010, Sato first became a triple crown trios champion with Michael Nakazawa and Tomomitsu Matsunaga and then also won DDT's top singles title, the KO-D Openweight Championship. Sato remained affiliated with DDT until January 2014. He is currently working for the All Japan Pro Wrestling promotion, where he is a former two-time World Junior Heavyweight Champion and four-time All Asia Tag Team Champion, while also being a five-time winner of the Jr. Tag Battle of Glory tournament.

The Pacific Wrestling Federation (PWF) World Junior Heavyweight Championship is a professional wrestling world title in Japanese promotion All Japan Pro Wrestling, contested exclusively among junior heavyweight wrestlers. It was created on July 31, 1986, when Hiro Saito defeated Brad Armstrong in a tournament final.