Yuki Yoza

Yuki Yoza was never the loudest person in the room. Step into the ring with him, though, and the message comes through loud and clear.

Born and raised in Ibaraki, Japan, Yoza was a quiet, timid child who struggled to assert himself. At six years old, his parents took him to observe a karate class at a local dojo – and then, something shifted. He felt a spark. The shy boy who rarely spoke up looked at the mat and told his parents he wanted to do it. That single moment set the course of his entire life.

Yoza threw himself into Kyokushin karate with a dedication that belied his gentle nature. The technical demands of the discipline suited his analytical mind perfectly, and as his skills sharpened, so did his confidence. He was even selected for the Japanese national team, as he tested himself at the highest levels of international competition and collected gold medals along the way.

Hungry for a new challenge, Yoza set his sights on professional kickboxing and began training at Hashimoto Dojo. He turned professional in 2019 and won seven fights that year, announcing himself as a legitimate talent and someone who needed to be taken seriously.

Then came a sobering stretch – two wins and two losses in his next four bouts. That episode forced him to take a long, honest look in the mirror.

What followed was one of the most courageous decisions of his career. For five years, Yoza had been working as a garbage collector, sleeping at 2 a.m., and rising at 5 a.m. to make ends meet. Meanwhile, he had been chasing his dream of being a Kickboxing World Champion on the side.

In order to achieve his dream, Yoza knew some pivotal changes would be necessary. With that, he made the decision to quit his job, commit entirely to kickboxing, and join a new gym where he could rebuild himself from the ground up.

The gamble paid off in spectacular fashion. Yoza embarked on a stunning run that carried him all the way to the K-1 Title in 2023. After rattling off a few more wins, the Japanese star signed with ONE Championship in April 2025 and proved he belonged with the world’s best strikers, defeating the likes of former ONE Bantamweight Kickboxing World Champion Petchtanong Petchfergus and ONE Flyweight Kickboxing World Champion Superlek.

Now competing on the global stage, the soft-spoken kid from Ibaraki has become one of Japan’s most feared strikers and “The Ace of ONE SAMURAI” won’t rest until ONE World Title gold is wrapped around his waist.