He has previously played in Major League Baseball (MLB) for the Arizona Diamondbacks and Seattle Mariners.

[4] During the 2017 season, his last before signing with a Major League Baseball team, the right-handed Hirano saved 29 games and pitched to a 2.67 ERA with 47 strikeouts in 57+1⁄3 innings.

[6] On December 22, 2017, Hirano agreed to a two-year, $6 million contract with the Arizona Diamondbacks.

[12] On February 6, 2021, Hirano signed a one-year, $1.4MM contract to return to the Orix Buffaloes of Nippon Professional Baseball, the team with which he had begun his career and pitched for from 2005 to 2017.

He became the 4th pitcher to reach over 250 saves, after Hitoki Iwase, Shingo Takatsu and Kazuhiro Sasaki.

Hirano played for the Japanese National Team at the 2017 World Baseball Classic.

[15] After advancing to the championship round, Japan lost to the United States 2–1 in the semifinal, finishing the tournament in third place.