Seiki Yoshioka (吉岡 世起, Yoshioka Seiki, born January 5, 1988), previously known as Seiki (stylized in all capital letters), is a Japanese professional wrestler currently working for Pro Wrestling Noah, where he is a former GHC Junior Heavyweight Champion, and a member of the Stinger stable, led by Yoshinari Ogawa. Yoshioka is also known for his time in Wrestle-1, where he was a three-time Wrestle-1 Cruiser Division Champion and UWA World Trios Champion and a one-time NWA International Lightweight Tag Team Champion in Pro Wrestling Zero1. In Wrestle-1, Yoshioka was a member of the #Stronghearts stable, led by Cima. In the past, Yoshioka has also toured Great Britain, as the final All Star Wrestling British Mid-Heavyweight Champion.