On 2/8, Kotari faced Yamato Hata for the super featherweight (under 59 kg) title of the Orient and Pacific Boxing Federation (OPBF) in Tokyo, Japan. The 12-round bout ended in a draw. Afterward, Kotari felt unwell and collapsed in the locker room.
At the hospital, doctors discovered the 1997-born boxer had a life-threatening brain hemorrhage and performed emergency craniotomy surgery. This surgery mandated Kotari's retirement under Japan Boxing Commission (JBC) rules.
![]() |
Shigetoshi Kotari (left) fights Yamato Hata in Tokyo, Japan, on 2/8/2025 for the OPBF super featherweight title. Photo: Naoki Fukuda |
Shigetoshi Kotari (left) fights Yamato Hata in Tokyo, Japan, on 2/8/2025 for the OPBF super featherweight title. Photo: Naoki Fukuda
On 4/8, the JBC announced that both Kotari and another boxer, Hirosama Urakawa, underwent craniotomy surgery and were under close observation. Sadly, four days later, the JBC announced Kotari's passing.
"Rest in peace, Shigetoshi Kotari," the World Boxing Organization (WBO) posted. "The boxing world mourns the tragic loss of this courageous athlete. Our condolences go out to his family, his team, and the entire Japanese boxing community."
Kotari was a well-known super featherweight boxer in Japan. His record stood at 8 wins, 2 draws, and 2 losses in 12 fights.
![]() |
Japanese boxer Shigetoshi Kotari dies at 28. Photo: WBO |
Japanese boxer Shigetoshi Kotari dies at 28. Photo: WBO
Following this tragedy, the OPBF implemented rule changes, reducing title fights to 10 rounds. The OPBF believes this measure will provide more time to prevent injuries similar to Kotari's.
Brain injury fatalities are not uncommon in the full-contact sport of boxing. In 2019, American boxer Patrick Day was knocked unconscious in the 10th round of a Chicago match, suffering a traumatic brain injury. Day fell into a coma after brain surgery and never regained consciousness.
Day's opponent, Charles Conwell, expressed remorse in an open letter to Day while he was in a coma. "I can’t stop thinking about it myself. I prayed for you so much and shed so many tears because I couldn’t even imagine how my family and friends would feel," Conwell wrote.
Earlier in 2019, the Russian Boxing Federation announced the death of Maxim Dadashev from injuries sustained in a match in Oxon Hill, Maryland. Trainer Buddy McGirt had asked the referee to stop the fight as Dadashev endured repeated blows. According to the Associated Press, Dadashev was admitted to UM Prince George's Hospital Center with brain swelling and did not survive.
According to a World Boxing Association (WBA) study, about 40% of boxers experience chronic traumatic encephalopathy (CTE). Symptoms may include cognitive decline, behavioral changes, or motor problems.
Compiled by Trung Thu