Ishii started Judo in 5th grade, and quickly became a regular of the winner’s podium. In 2006, at 19 years and 4 months old, he became the youngest National Champion by defeating 2004 Athens Olympic gold medalist, got him the ticket to the Beijing Olympics. Ishii won the gold medal during the Olympic judo games by winning 4 matches by ippon and showed his potential to the max. 3 months later, he announced his transition on becoming a professional fighter. Ishii made bitter MMA debut in 2009 against former Olympic gold medalist Hidehiko Yoshida which he dropped by decision, but since then he has trained abroad and have built a significant record. Ishii will be making his appearance in the tournament to once again, achieve the world title.