At the March 20, 2015, Real Japan event, Sayama was defeated by All Japan wrestler Akebono following a splash from the former yokozuna. Afterwards, Sayama began experiencing chest pains, which forced him to pull out of subsequent matches. After multiple tests, it was determined that Sayama needed to undergo emergency heart surgery, which took place on May 22. Following the surgery, Sayama began suffering from angina, which forced him to pull out of Real Japan's 10th anniversary event on June 11. On June 5, Sayama held a press conference, stating that he was not thinking about retiring from professional wrestling despite his life being in danger prior to the catheter surgery. Sayama returned to the ring on June 23, 2016, battling Minowa-man to a draw, but has not been back since then.