He has previously played in Nippon Professional Baseball (NPB) for the Fukuoka SoftBank Hawks and Tokyo Yakult Swallows.
In 2011 Nippon Professional Baseball draft, Fukuoka SoftBank Hawks selected Kayama in the fifth round.
[1] On Nay 4, 2012, Kayama debuted in the Pacific League against the Tohoku Rakuten Golden Eagles as a relief pitcher.
He changed the three-quarter overhand pitching foam to sidearm in the fall training and learned the slow curveball.
[9] In the match against the Tokyo Yakult Swallows in the Interleague play on June 18, 2019, he recorded a save for the first time.
[14] He achieved his 100th career Holds on October 5 against the Tohoku Rakuten Golden Eagles.
[16] He signed a two-year contract with the team for an estimated salary of 160 million yen plus incentives without exercising his domestic free agent rights.