Shootboxing and KNOCK OUT Champion Renta Nishioka Announces Retirement

Apr 02, 2023
Renta Nishioka after winning the KNOCK OUT belt in 2020. Photo: KNOCK OUT
The two organization champion retired due to severe bone and cartilage damage.

The world of professional kickboxing has lost one of its' finest competitors.

Renta Nishioka, the former Shootboxing Lightweight (-62.5 KG) champion and the 2020 KNOCK OUT -64 KG Grand Prix winner has announced his retirement from professional competition due to severe cartilage deterioration and bone deformation in his left wrist.

Nishioka first underwent wrist surgery at the age of 17, two years into his professional career. The damage was gradually exacerbated during the next three years. He was forced to undergo surgery again in late 2020, following a unanimous decision loss at the hands of Kento Haraguchi. Although Nishioka returned in 2022, following a two-year break from the sport, the pain in his wrist persisted. After consulting three separate physicians in Tokyo, Saitama, and Chiba, Nishioka was informed that the cartilage in his wrist was all but gone, while the bones became deformed after grinding against each other due to the aforementioned lack of cartilage.

All three physicians recommended retirement as no reconstructive or reparative surgery was possible at that stage. During the course of his seven-year-long career, Nishioka was able to become a champion in two separate organizations and has overcome a number of notable fighters, such as Chihiro Suzuki, Fukashi Mizutani, and in his last walk to the ring, Hiroki Suzuki.

In a social media post published today, Nishioka stated: "I started martial arts when I was 5 years old, and now it's been 18 years. I can't say that I don't have any regrets, but I have had the fortune of getting a lot of encouragement and support. Ultimately, I think I was given a great life as a fighter. I have nothing but gratefulness and kind words for everyone that has supported and helped me along the way. Thanks for everything. Although my life as a fighter ends here, life continues, so I would be happy if you continue to support me."