During the 2014–2018 season with the Swallows, he contributed to the team as a setup man. In all, he pitched in 283 games with a 19–17 Win–loss record, a 2.68 ERA, 67 Holds, 34 Saves, and 274 strikeouts in 298.2 innings.
On 16 July 2016, Akiyoshi was named an All-Star and pitched in the 2016 Mazda All-Star Game 2016.
On 12 April 2019, he recorded his first save since joining the Fighters.
Akiyoshi played the 2019–2021 seasons with the Hokkaido Nippon-Ham Fighters, he contributed to the team as a Closer. In all, he pitched in 96 games with a 1–6 Win–loss record, a 4.04 ERA, 11 Holds, 37 Saves, and 84 strikeouts in 91.1 innings.
On 16 November 2021, he elected free agency following the 2021 season.
Fukui Nexus Elephants
On 31 January 2022, Akiyoshi signed with the Fukui Nexus Elephants of the independent league Nihonkai OCEAN League.
He recorded 18 Games pitched, a 1–2 Win–loss record, a 2.66 ERA, 7 Saves, and 35 strikeouts in 20.1 innings.
Fukuoka SoftBank Hawks
On 19 July 2022, Akiyoshi signed with the Fukuoka SoftBank Hawks. On 3 August, he made his debut as a pitcher for the Hawks. He pitched in only two games in the Pacific League in the 2022 season.[citation needed]
On 17 October 2022, the Hawks announced he was a free agent.
International career
On 15 February 2016, Akiyoshi represented the Japan national baseball team at the Samurai Japan Warm-up Game Japan vs Chinese Taipei.
