He has previously played in NPB for the Tokyo Yakult Swallows and Yomiuri Giants.

[1] On September 29, 2016, Hirooka debuted in the Central League against the Yokohama DeNA BayStars, and recorded his first Home run.

[2] In 2016 - 2020 season, he recorded in 236 games with a batting average of .214, a 21 home runs, a RBI of 54.

In 2022, Hirooka played in only 28 games for the Giants, struggling to a .180/.293/.280 slash line with no home runs and 4 RBI.

[citation needed] This biographical article relating to a Japanese baseball infielder is a stub.