Yutaka Mukaiyama (向山裕, Mukaiyama Yutaka; born December 15, 1966) is a Japanese pornographic actor and a former professional wrestler better known as Chocoball Mukai (チョコボール向井, Chokobōru Mukai). Beginning his career in 1990s, Mukai became one of the more well known JAV stars in all of Japan, and holds the record for being the highest paid AV actor ever, earning over ¥20 million JPY at the height of his fame. Initially wanting to be a professional wrestler, Mukai returned to his passion and joined Frontier Martial Arts Wrestling (FMW) in 1999, competing for the promotion as well as IWA Japan until his retirement.
Source: “Chocoball Mukai”, English Wikipedia (CC BY-SA 4.0), excerpt