He played association football until the first year of junior high school, when he took up boxing under the guidance of his father and uncle.
He made his debut against Yuki Sueyoshi on 20 April 2014, in the quarterfinals of the West Japan light flyweight Rookie of the Year tournament.
[2][3] Akui was given an automatic pass for his semifinal bout, which was expected to take place in July 2014, as his opponent pulled withdrew.
[5] Akui entered the 2015 West Japan Rookie of the Year light flyweight tournament as well, and was scheduled to face Ruka Shobu in the quarterfinals on 19 July 2015.
[7] Akui was scheduled to fight Hiroki Hosoya for the All Japan Rookie of the Year light flyweight title on 20 December 2015.
[9] Akui faced a large step up in competition on 3 December 2016, when he scheduled to fight Kenji Ono on a G+ televised card.
[14] Akui was scheduled to face the future WBC light flyweight champion Masamichi Yabuki on 8 April 2018.
[20] Akui was scheduled to make his first title defense against the #1 ranked JBC flyweight contender Seiya Fujikita on 18 October 2020.
[26] Akui faced the #14 ranked WBC light-flyweight contender Jayson Vayson in a ten-round flyweight bout on 4 February 2023.
[28] On August 4, 2023, the WBA formally ordered their flyweight champion Artem Dalakian to make a mandatory championship defense against Akui.
[36] Akui previously faced Kuwahara in a Japanese flyweight championship bout on July 21, 2021, when he twice knocked him down en route to winning the fight by a tenth-round technical knockout.
Two of the ringside officials scored the fight 117–111 in his favor, while the third judge awarded Akui a slightly wider 118–110 scorecard.