Nippon Sport Science University
After graduating from high school, Sato had to spend a year as a ronin and started to train in shoot wrestling under Noboru Asahi and Noriaki Kiguchi in the Kiguchi Dojo, partnered with the Shooto promotion. He later moved to amateur wrestling after being admitted in the Nippon Sport Science University, and after graduating in 1994 and competing in the All Japan Amateur Shoot Championships, he joined professionally the company.