Rui Okubo

Kickboxing Featherweight, -57.5 kg; previously also Super Bantamweight and Flyweight

On his 22nd birthday, Rui Okubo has the chance to crown himself K-1 Featherweight champion at Yoyogi Stadium, becoming the youngest figurehead of the new K-1 generation, having come through the organization’s own youth development program.

Profile

The story

Okubo advanced to the professional circuit after an exceptional amateur career and progressing through Japan’s K-1 youth system. Within four professional fights, he won the inaugural Krush Flyweight title and later reached the final of the K-1 WORLD GP Super Bantamweight tournament.

At K-1 WORLD MAX 2026, he will face Ryota Ishida for the Featherweight title on his birthday. As a young challenger, he embodies the progression from Japan’s youth and amateur system to the main stage.

In the ring

Fighting style

Okubo is a technically skilled orthodox fighter with a strong foundation in point-fighting and gloved karate-style stand-up. In the professional circuit, he developed into a versatile kickboxer with both decision wins and knockout power.

Results

Performance

Inaugural Krush Flyweight Champion (-51 kg, 2022); finalist of the K-1 WORLD GP Super Bantamweight Tournament (2024); Japan Cup Champion (2021); K-1 Koshien Champion (2021); K-1 All Japan A-Class Champion (2021); professional record reportedly around 10–13 wins against 2 losses according to various sources; amateur record reportedly 145–18–3.

Over the years

Timeline

12 September 2004: born in Utsunomiya, Tochigi Prefecture, Japan
Around 2010: starts kickboxing at the age of six
2021: wins the Japan Cup, the K-1 Koshien tournament, and the K-1 All Japan A-Class Championship
February 27, 2022: professional debut
2022: captures the inaugural Krush Flyweight title within four fights
2024: reaches the final of the K-1 WORLD GP Super Bantamweight tournament and loses to Riamu
February 8, 2026: faces Akihiro Kaneko in a rematch and comes in overweight
September 12, 2026: scheduled title challenge against Ryota Ishida at K-1 WORLD MAX 2026, on his 22nd birthday

Influence

Legacy

As one of the youngest challengers on the card and a product of K-1’s own youth and amateur system, Okubo embodies the progression of a new Japanese generation onto the main card. However, his career is still taking shape and does not yet have a complete, iconic story.