Miura, now 12-6 in MMA, began his combat career in Pancrase back in 2004 and remained an MMA fighter until 2009, fighting in several K1 and WEC shows along the way. In 2010 he debuted as a boxer, fighting in the US, and would win his first 9 boxing bouts before coming up short in October 2012 against Yuzo Kiyota for the OPBF Super Middleweight title. That loss later resulted in him turning back to MMA and he has since won 3 fights, including this bit win over Murayama.
Although the 35 year old is never likely to return to boxing this win is something that will stand out as his biggest achievement in combat sports. Given his age his title reign may be short, but it's certainly an achievement to claim a title in Pancrase, one of the toughest MMA leagues out there.