Fukuda was a member of the Yamanashi Gakuin University's wrestling team. At the All Japan University Championships, he placed third in 2002 and second in 2003 in his weight class. Fukuda then joined a pro-wrestling organization called WJ (started by a popular pro-wrestler Riki Chōshū) and made his pro-wrestling debut in March 2003. He switched to the Killer Bee mixed martial arts team in 2004.
In his MMA debut fight at Superbrawl, Fukuda surprised many by taking Joe Doerksen to decision. Over the years, he has worked for the Japanese promotions Shooto, Pancrase and K-1. In February 2007, he made his debut in the US EliteXC promotion at EliteXC Destiny. He then lost a close decision to Joey Villasenor on the September 15, 2007 EliteXC: Uprising card. He currently fights for the Japanese MMA promotion DEEP.
More recently, Fukuda fought at DREAM.8 as a late replacement for Yoon Dong-Sik, where he defeated Murilo Rua by unanimous decision. At DEEP 42, Riki defeated Yuichi Nakanishi via unanimous decision to become the DEEP Middleweight Champion. Fukuda successfully defended the title against Hiromitsu Kanehara at DEEP 46. He has a record of 16 wins and 4 losses.