Minowa made his professional debut in the Lumax Cup in 1996, but would spend most of his early career in the Pancrase promotion. Minowa had a poor start to his MMA career, going 1-8-1 in his first ten fights, taking on MMA pioneers such as Yuki Kondo and Jason DeLucia, and with the win being in his Pancrase debut. The young Minowa would turn his career around, however, improving to 12-11-6 with a win over Daiju Takase before fighting in his first and only fight in the UFC at UFC 25 in Tokyo, Japan. The bout was against Joe Slick and Minowa won via TKO from a cut that Slick received.
Minowa continued to fight in Pancrase as well as another Japanese organization, DEEP, before making his PRIDE debut against future UFC Light Heavyweight Champion Quinton "Rampage" Jackson.
Minowa was known in PRIDE for his entertaining entrances and sporting of the Japanese flag as a cape as well as his aggressive, high-risk style of fighting which has seen him employ flying dropkicks amongst other pro-wrestling derived maneuvers. It was also during his career with PRIDE that he continued to cement his legacy in taking on fighters that were much bigger than himself, winning most of the Openweight bouts and earning the nickname "The Giant Killer".
He participated in PRIDE's first 185 lb tournament where he won over Phil Baroni, but went on to lose in the second round to former UFC Middleweight Champion Murilo Bustamante. On December 31, 2005, Minowa fought the legendary Kazushi Sakuraba, in which he almost landed a kneebar and then a heel hook, but was caught with a Kimura lock and defeated at nine minutes into the first round. Minowa next fought at PRIDE Bushido 10, where he faced the 7-foot-2 Giant Silva. Minowa dominated the fight, using a forward roll to get past Silva's enormous reach and then landing a single leg takedown that put Silva on his back. Minowa promptly landed multiple knees to the head of Silva, causing the referee to stop the fight at 2:23 of the first round. Following that, he fell to Mirko Cro Cop due to strikes in the first round. However, he then rebounded with wins over Park Hyun Kab, Eric "Butterbean" Esch, and American professional wrestler Mike Plotcheck.
Minowa was knocked out in his last fight for PRIDE by Kiyoshi Tamura at PRIDE Shockwave 2006, but celebrated 10 years as a fighter at the CMA Festival 2 event by defeating Min-Seok Heo in the main event after his opponent's corner threw in the towel after the first round. His next opponent was South Korean wrestler Choi Seung Hyun at Heat4: Mega Battle Heat from Nagoya. Minowa won the bout via shoulder lock.
He fought MMA legend and former mentor Masakatsu Funaki at the DREAM 6 event on September 22, 2008. He was submitted in the first round via heel hook.
At DREAM 8 he lost via decision to professional wrestler Katsuyori Shibata, after being suplexed by the young Japanese fighter, but rebounded at Dream 9 defeating Bob Sapp in what was his 80th fight.
He faced the 7'2" 319 lb Choi Hong-man at DREAM 11 on October 6, 2009. Throughout the fight he attempted to take his opponent down, being successful on two occasions in the first round, before submitting his opponent in the second.
At Dynamite!! 2009 Minowa squared off with Cameroonian fighter Rameau Thierry Sokoudjou in the finals of the DREAM Super Hulk tournament. In the first round Sokoudjou landed many strikes on the smaller fighter while Minowa attempted leglocks. At the end second round Minowa had Sokoudjou in a kneebar but was cut off by the bell before he could adjust his grip. In the third round Minowa and Sokodjou both received two yellow cards (10% purse deduction for one) for inactivity 3 minutes into the round, but with 90 seconds left Minowa sprang forward and connected against Sokoudjou's jaw with a left hook, dropping him to the ground for the TKO victory and winning the Super Hulk Tournament.
Minowa went on to fight American Super Heavyweights Jimmy Ambriz and Imani Lee at DREAM 13 and DREAM 14 respectively, winning both fights by submission.
Then for DREAM 16, Minowa was scheduled to fight James Thompson but three days before the event, had his opponent switched to Satoshi Ishii and he lost by unanimous decision.
Minowa next faced Chang Hee Kim of South Korea at DEEP: 50th Impact on October 24, 2010. Minowa gave up a significant weight advantage to Kim, who weighs over 300 pounds. He won the fight via submission in the first round.
Minowa faced Kendall Grove at ProElite 3 on January 21, 2012. He lost the fight by unanimous decision.
Minowa faced debuting MMA fighter Goran Jettingstad at IGF 1 on April 5, 2014. He won by submission (lateral kneebar).
Minowa then faced Jung-Gyo Park at ROAD FC 15 on May 31, 2014. Minowa lost the bout via KO late in the first round.
Minowa faced Shinichi Suzukawa at IGF: Inoki Genome Fight 2 on August 23, 2014. He lost the fight via corner stoppage TKO in the second round.
Recently, Minowa has turned his attention to professional wrestling. On 22 February 2010, Minowaman made his debut for Antonio Inoki's IGF facing and defeating Necro Butcher in a 10-minute match.
Minowa has also undertook some additional professional wrestling training under the tutelage of Satoru Sayama, the original Tiger Mask. On July 18, 2010, Minowa debuted as the fifth generation Tiger Mask.DREAM
2009 DREAM Super Hulk Grand Prix Champion
Pancrase Hybrid Wrestling
1999 Neo Blood Tournament Winner
2000 King of Pancrase Light Heavyweight Championship Tournament Runner-Up
1997 Neo Blood Tournament Semifinalist
PRIDE Fighting Championships
2005 PRIDE Welterweight Grand Prix Semifinalist