Early career

Hiromi began a six fight winning streak with a first-round TKO win over Kazunari Kimura.^[5][6] During this run he likewise scored knockouts over Yoichi Yamazaki,^[7] Shimada Masayuki and Tanaka Yuki.^[8] Wajima won the rematch with Jinbo Katsuya during KHAOS 5, with a second-round KO.^[9]

Hiromi Wajima had his second professional career loss with a unanimous decision loss to Jordann Pikeur.^[10][11] He suffered his first knockout loss at the hands of Minoru Kimura, losing after only two minutes.^[12]

He snapped his losing streak at Krush 108, where Wajima won a unanimous decision against Daisuke Fujimura.^[13]

Wajima participated in the 2020 Super Welterweight Grand Prix. In the quarter final bout he faced Avatar Tor Morsri whom he defeated early in the third round with a leg kick knockout. In the semifinals he won a unanimous decision against Yasuhiro Kido. In the grand prix finals he fought a rematch with Minoru Kimura. He would fail to capture the super welterweight title, losing to Kimura for the second time in his career.^[14][15][16]

Wajima fought Raseasing Weerasakreck during K-1 World GP 2020 in Osaka. He won the fight by a second-round KO.^[17] He was scheduled to fight Yuhei Fujioka during K-1 World GP 2020 in Tokyo,^[18] and won by a second round head kick.^[19]

Wajima was scheduled to fight Abiral Ghimire at K-1 World GP 2021 in Fukuoka on July 17, 2021.^[20] He won the fight by a third-round technical knockout.^[21]

K-1 super welterweight champion

Wajima challenged Minoru Kimura for the K-1 Super Welterweight title at K-1 World GP 2021 in Osaka on December 4, 2021. They previously fought on March 22, 2020, with Kimura winning by a first-round technical knockout.^[22] Wajima was more successful in the rematch, winning the fight by a third-round knockout. He began to take over the fight from the beginning of the second round onward, with most of his success coming from body strikes, and finally stopped Kimura with a body kick which left him unable to beat the eight count.^[23]

Wajima was booked to face the former RISE welterweight champion BeyNoah at The Match 2022 on June 19, 2022.^[24] He won the fight by unanimous decision, with all three judges scoring the bout 30–24 in his favor, as he managed to knock BeyNoah down in every round of the fight.^[25]

Wajima faced the former FFC Lightweight (70.3 kg) champion Meletis Kakoubavas in a non-title bout at K-1 World GP 2022 Yokohamatsuri on September 11, 2022.^[26] He won the fight by a first-round knockout. The fight was stopped early in the opening round, as Wajima landed an inadvertent low blow on Kakoubavas.^[27]

Wajima made his first K-1 Super Welterweight title defense against the four-weight Rajadamnern Stadium champion Jomthong Chuwattana at K-1 World GP 2023: K'Festa 6 on March 12, 2023.^[28] The fight was ruled a majority decision draw after the first two rounds, with two judges having scored the bout an even 29–29, while the third judge awarded Wajima a 29–28 scorecard. Wajima won the fight by technical knockout 25 seconds into the extra fourth round.^[29]

Wajima made his second K-1 Super Welterweight title defense against the Krush Super Welterweight champion Jordann Pikeur at K-1 World GP 2023 on July 17, 2023.^[30] He won the fight by a second-round knockout.^[31]

Wajima made his third K-1 Super Welterweight title defense against the Wu Lin Feng -70 kg champion Ouyang Feng at K-1 ReBIRTH 2 on October 10, 2023.^[32] He lost the fight by a second-round knockout.^[33]

Wajima faced Darryl Verdonk at K-1 World MAX 2024 - World Tournament Opening Round on March 20, 2024. He lost the fight by a first-round technical knockout.^[34]