He began his professional career in 2002, fighting in the GCM promotion and Pancrase, as well as making an appearance at Pride FC: The Best, Vol.
[1] Okami continued fighting in multiple promotions before arriving at Rumble on the Rock, where he entered a 175 lb tournament.
Anderson Silva, Frank Trigg, Carlos Condit, and Jake Shields also competed in the tournament.
In the opening round, Okami fought the future UFC Middleweight Champion Anderson Silva.
Okami's knees were on the ground at the time, making the attack an illegal strike to the head of a downed opponent.
"[2] Referee Troy Mandaloniz held Silva back and gave the wobbled Okami time to recover.
Silva responded by asserting he "felt it was a cheap, cowardly way of winning," and that "people that were there saw that he was in the condition to come back and keep fighting, and he didn't.
"[3] Moving on to the next round, Okami faced the future EliteXC welterweight and Strikeforce Middleweight Champion Jake Shields, a tournament favorite.
Though Dana White said that the winner might earn a title shot, the fight was placed on the undercard, possibly due to the fighters' lack of fan support.
[5] Okami dominated the fight with superior stand-up, takedown defense, and ground control en route to a unanimous decision victory.
Okami was scheduled for a rematch with Anderson Silva for the Middleweight Championship at UFC 90, but he was forced to drop out of the bout due to a broken hand.
After his recovery, Okami faced 2003 ADCC Absolute Division gold medalist Dean Lister at UFC 92 and earned a unanimous decision.
Lister made frequent attempts to pull guard and take Okami down to the ground, but was not able to secure any submissions.
Okami was next scheduled to return at UFC 98 against Dan Miller, but suffered a torn ligament and was not able to compete.
On August 1, 2010, Okami defeated Mark Muñoz via split decision in the co-main event at UFC Live on Versus: 2.
[10] Belfort was then pulled from the fight, and Nate Marquardt was tapped to make a quick return to face Okami.
[11][12] Okami was able to control the center of the octagon and dictate the pace of the fight en route to a unanimous decision victory in what was a closely contested bout.
Okami next faced former Bellator Middleweight Champion Hector Lombard at UFC on Fuel TV: Silva vs. Stann on March 3, 2013.
[21] When asked via Twitter why he released Okami, UFC President Dana White remarked "Our roster is packed.
"[22] When asked by Yahoo Sports why he was releasing a highly ranked fighter who had won three of his last four bouts, White responded: "He was always a tough guy and was right up there, but it's almost like he'd become a gatekeeper.
Okami was scheduled to face Ryan Ford in the main event of WSOF 21 on June 5, 2015.
[29] On July 30, 2015, it was announced that Okami would be moving down to the welterweight division and facing Jon Fitch on October 17, 2015, at WSOF 24.
Despite less than a week notice, Okami had stated he was preparing for a potential fight at Middleweight, but jumped on the opportunity for another shot with the UFC.
[42] Okami won his next fight against Agilan Thani by split decision at ONE Championship: Century on October 13, 2019.
[45] After over three years of inactivity, Okami was scheduled to face former ONE Middleweight and Light Heavyweight World Champion Aung La Nsang at ONE on Prime Video 4 on November 19, 2022.