A professional competitor since 2006, he has fought for DREAM, Pancrase, DEEP, M-1 Global, ProElite, ONE FC, K-1, and also participated in the Dynamite!!
Mizuno started competing in judo in high school, and currently holds a 3rd dan black belt in the discipline.
On July 16, 2011, Mizuno defeated Trevor Prangley by KO (knee to the body) in the first round at Dream: Japan GP Final.
[5] On January 21, 2012, Mizuno defeated Ilima Maiava via submission (arm-triangle choke) in the second round.
[6] In June 2012, Mizuno faced MMA veteran Renato Sobral at ONE Fighting Championship: Destiny of Warriors.
[9] In Mizuno's next bout, he faced undefeated Brazilian Leandro Ataides at ONE Fighting Championship: Rise of Heroes on May 2, 2014.