He debuted in MMA over a decade ago, and trains and fights out of Wajitsu Keishukai, where he teaches once a week.

[citation needed] Osawa's fight record is 21-11-2 and has competed in many of the top organisations such as Shooto, WEC, DREAM and DEEP.

[citation needed] He was scheduled to fight Brazilian jiu-jitsu ace Rani Yahya on August 9, 2009, at WEC 42, but due to a foot injury, he was replaced by John Hosman.

[3] Osawa lost via unanimous decision to Antonio Banuelos on November 18, 2009, at WEC 44 and was subsequently released from the promotion.

[4] Osawa made his DREAM debut against Yoshiro Maeda at DREAM.14 on May 29, 2010, winning a close split decision.