Katsunari Takayama will be remembered as a fighter who won five world titles in boxing's smallest weight class but also one challenging the establishment in Japan.

Takayama was born in Osaka, Japan on May 12, 1983 and his early years were much like any other child growing up in the country.

"I was a quiet child and liked sweets, so was chubby in primary school," Takayama told The Ring through Ryohei Maio. "I played rugby in middle high school; my position was hooker."

He didn't find boxing until he was 14 but it didn’t come easily.

"In the very first sparring session, I got the nosebleed," he recalled. "Then I fought as hard as I could. Sometimes I was hit hard in sparring, but could feel myself improving and getting stronger, so was absorbed by boxing."

With no amateur experience at the age of 17, he made his professional bow against fellow debutant Yozo Nakamura, earning in the region of $200, scoring a fourth-round stoppage in October 2000.

After notching 10 consecutive wins, he lost his unbeaten record to Masato Hatakeyama in nine rounds for the Japanese junior flyweight title in April 2003.

The fight was a learning curve for Takayama, who won four fights to secure a fight with WBC strawweight titleholder Isaac Bustos in Osaka, in April 2005.

"My coach advised me in first three rounds, you have to take the points and take control,” said Takayama, who won a 12-round unanimous decision. "Fortunately, our plan went well. I caught my rhythm of boxing.

"I got a lot of relationships, friends, sponsorships, partnerships and confidence in myself."

However, he dropped the title in a 12-round points defeat by Eagle Den Junlaphan four months later in Tokyo.

"Once I lost the title 95 percent of them disappeared," he said in an all too familiar tale.

Over the next couple of years, he came up short in title attempts against Yutaka Niida (SD 12) and Roman Gonzalez (UD 12).

"Against Gonzalez, although I lost, I really appreciate and respect him, he fought like the champion,” he said. “After the bout, I was put in the hospital because of serious bleeding. Gonzalez was also seriously damaged. He needed oxygen, his hands and legs temporarily paralyzed and urine was red."

It was at this point that Takayama made the stunning move to give up his JBC license and went overseas to continue his career.

"Japan only recognized the WBA and WBC titles," he said. "That's why I decided to go abroad.

"Once I retired the JBC [license], a lot of boxing gyms turned me down, even to use the gym for training."

After a 14-month absence, Takayama resurfaced in South Africa where he won an IBF eliminator with a sixth-round stoppage of Tshepo Lefele. He parlayed that into an IBF title fight with Nkosinathi Joyi, also in South Africa. A third-round clash of heads meant the fight was declared a no-contest, with Joyi prevailing via unanimous decision in their rematch.

Takayama then headed to the Philippines where he lost a 12-round split decision to Mateo Handig in another eliminator. His future looked bleak when offered a fight against Joyi's conqueror Mario Rodriguez in Mexico for the IBF strap. Takayama recovered from a third-round knockdown, going on to win a 12-round points decision.

Takayama scored a huge win when the JBC accepted the IBF and WBO, changing their rules on April 1, 2013, to allow those two sanctioning bodies entry into the Japanese market. That saw Takayama make two home defences, outpointing Vergilio Silvano and Shin Ono over 12.

He met WBO counterpart Francisco Rodriguez Jr. for a world title unification in Monterrey, Mexico and fell short via 12-round unanimous decision during their August 2014 meeting.

"Great fight," he said. "Sometimes Francisco Rodriguez was near to giving up the fight, but the loud cheering of his hometown fans kept him going.

"One of the most memorable scenes was TV commentator, Julio Cesar Chavez was standing up and cheering at the top of his lungs."

Rodriguez elected to vacate and move up in weight, opening the door for Takayama to win both belts with a seventh-round stoppage of compatriot Go Odaira in December 2014.

He vacated the WBO title but made two successful defenses of the IBF belt against Fahlan Sakkreerin Jr. (TD 9) and Ryuji Hara (TKO 8) before losing to Jose Argumedo (TD 9) but later regained the vacant WBO title when beating Riku Kano (TD 6).

Takayama decided to make the unprecedented move of retiring from professional boxing with a clear goal of representing Japan at the 2020 Tokyo Olympics.

"At that time, in Japan, there was a high barrier to separate pros and amateurs," he explained. "We did everything to break the barrier, there was a lawsuit, doing a signature campaign, and went to IBA in Lausanne, Switzerland to appeal directly.

"Finally, through the legal battle, I was eligible to participate in amateur tournaments [to qualify] for the Olympics. Unfortunately, I could not qualify."

Takayama returned to the pro ranks and after one win, he fought WBO junior flyweight titlist Elwin Soto on two weeks' notice as part of the Canelo-Saunders undercard in May 2021.

Takayama brought the curtain down on his career and intends to try to give help others.

"I retire in good health and without serious damage," said Takayama (35-9, 12 KOs). "I work at the Yoneda pharmacy of my long-time sponsor.”

Takayama, now 42, is single and lives in Osaka. He graciously took time to speak to The Ring about the best he fought across 10 categories.

Nkosinathi Joyi: "There was no wasted motion, and it was difficult to dodge."

Eagle Den Junlaphan: "His slipping away was excellent."

Roman Gonzalez: "He stood very relaxed and kept his proper distance, was really good at measuring his favorite distance."

Gonzalez: "Gonzalez, Joyi and Argumedo were throwing punches that were difficult to anticipate, but I would say Gonzalez.

His combinations were so hard to anticipate and see, I had never experienced that before. There were a lot of combination variation, so troublesome to dodge."

Gonzalez: "Gonzalez, Joyi and Eagle Den Junlaphan. I tried to annoy them with my footwork, but they stayed calm and coped with my tactics.

I'd say Gonzalez, he had a sharp eye to opponent's tactics. In our fight, he saw through my tactics to escape to the left in only two rounds. He turned his body to the right, making my circling impossible and had an amazing ability to adapt.

Jose Argumedo: "However hard I hit Argumedo, wherever I hit him, he kept on coming forward like a tank without any trouble. It was creepy."

Mario Rodriguez: "My best shot landed and didn't even wobble him at all."

Joyi: "Especially his straight right hand. It was very difficult to perceive because there was no movement before he threw the punch. He shook my knees several times."

Gonzalez: "Outstanding combinations, especially left hook combinations which were very difficult to dodge."

Gonzalez: "I believe that the essence of boxing is 'hit and not hit.' Gonzalez can control a bout like that. He has a keen ability to predict danger. When I faced him, he seemed like a fortune-teller. When I try to throw the blow in my mind, he would stay away and throw a punch or combination back."