Seiya Tsutsumi

Tsutsumi made professional debut on March 27, 2018, winning the bout by KO in the first round.^[1]

Then, in September 2019, Tsutsumi transferred to Kakuebi Geki Boxing Gym.^[2] After that, he entered the GOD'S LEFT bantamweight tournament as a seed in the first round and entered the semi-finals, and was scheduled to compete in the semi-finals against Kenya Yamashita at Korakuen Hall on November 9 of the same year, but the match was canceled due to Yamashita's withdrawal.^[3] He advanced to the finals with a bye.^[4]

On January 28, 2020, Tsutsumi faced Kazuki Nakajima, ranked 6th in the Japanese bantamweight division, in the tournament final. The match ended in a majority draw at 0-1 (75–77, 76–76, 76–76) after 8 rounds.^[5]

On October 26, 2020, Tsutsumi faced Daigo Higa, a former WBC world flyweight champion. The fight ended in a majority draw, one judge scoring it in favour of Higa, 96–94, while the other two judges saw the fight as a draw, scoring it 95-95.^[6][7]

On June 23, 2022, Tsutsumi fought against Japanese bantamweight champion Kyosuke Sawada. He won the bout by TKO at 47 seconds in the 8th round, successfully winning the title.^[8]

On October 20, 2022, in his first Japanese bantamweight title defense, Tsutsumi faced Kenshin Oshima, the 6th ranked Japanese bantamweight. He won the by TKO at 2 minutes and 42 seconds in the 9th round, successfully defending his title for the first time.^[9]

On March 20, 2023, in his next Japanese bantamweight title match, Tsutsumi faced Minamide, the No. 1 ranked Japanese bantamweight. He won by TKO at 1 minute 41 seconds in the seventh round, successfully defending his title for the second time. In addition, his opponent Minamide retired from active duty after this match.

On March 31, 2023, it was announced that Tsutsumi would be seeded in the first round and participate in the semi-finals of the Ohashi Boxing Gym's Monster Tournament.^[10]

Tsutsumi faced Kazuki Anaguchi on December 26, 2023, on the undercard of Naoya Inoue vs Marlon Tapales. He won the bout by unanimous decision after four knockdowns during the bout to successfully defend his Japanese bantamweight belt.^[11] Anaguchi never regained consciousness, dying six weeks later.^[12][13]

Tsutsumi vacated the Japanese bantamweight title on January 6, 2024, in order to pursue a world bantamweight title.^[14]

Tsutsumi challenged Takuma Inoue for his WBA bantamweight title at Ariake Arena in Tokyo, Japan on October 13, 2024.^[15] He won the fight and the title by unanimous decision.^[16]

Tsutsumi made the first defense of his WBA bantamweight title against Daigo Higa at Ariake Arena in Tokyo, Japan on February 24, 2025.^[17] The fight ended in a draw with all three judges scoring it 114–114.^[18]

On March 26, 2025, the WBA ordered Tsutsumi and interim champion Antonio Vargas to hold a unification bout for the WBA World Bantamweight Championship. Negotiations were due to end on April 25, 2025, and if no agreement was reached, a bidding process would be held. While standard WBA rules require a champion to defend their title against a designated challenger within 120 days of acquiring the new belt, the uncertainty surrounding Tsutsumi's designated challenger and the expiration of the designated title defense period led to the decision to hold the unification bout against Vargas.^[19] On May 13, 2025, however, Tsutsumi announced on social media that he had undergone surgery to treat a two-year-old left eye condition, preventing him from competing in the unification bout scheduled for July of the same year. As a result, the WBA designated Tsutsumi as champion in recess effective May 17, 2025. He is the third Japanese boxer to hold a world title and have been recognized as a champion in recess by the WBA, following Tomonobu Shimizu and Koki Kameda. Thus, interim champion Vargas was promoted to regular champion on the same day.^[20][21]

Tsutsumi is scheduled to face WBA interim bantamweight champion Nonito Donaire in a title unification bout at the Ryogoku Kokugikan on December 17, 2025. He was originally scheduled to fight WBA regular champion Antonio Vargas, but Vargas was unable to fight due to the death of his mother, and on December 1, the WBA declared Vargas champion in recess and Tsutsumi was reinstated as champion.^[22] Tsutsumi defended the title by split decision.^[23][24]