Naoya Inoue made it to the pinnacle of his sport with a destructive upward surge through boxing’s weight classes not seen since Manny Pacquiao’s prime. And he has made it clear he plans to stay there in the final run-up to his toughest test yet against unbeaten rival Junto Nakatani in their sold-out dream fight at the Tokyo Dome on Saturday.

Speaking at a press conference at the Tokyo Dome Hotel on Thursday, the undisputed super-bantamweight champion struck a composed tone ahead of one of the most anticipated bouts of a sparkling career that flew past the Hall of Fame threshold years ago.

“There’s only one thing: I’m determined to win in two days,” Inoue said.

Athletes like Inoue do not come along often. The 5ft 5in knockout merchant known as the Monster captured his first world championship at 108lb in just his sixth professional outing before adding a second title at 115lb in his eighth, then unifying all four major belts at 118lb and 122lb in a 378-day span. At 33, he is already one of the finest fighters at any weight from any era: a true superstar with a taste for devastating finishes that belies his polite mien. He is the greatest show in sports today.

But fights like Saturday’s are even rarer in a sport where the best seldom face off in their primes. Both men enter with identical 32-0 records and world titles at multiple weights. Both are fixtures in the pound-for-pound conversation, with Inoue at No 2 and Nakatani at No 6 on Ring Magazine’s most recent list.

It is being billed as the biggest fight in Japanese boxing history and this time the promotional bluster may even be true: two undefeated homegrown stars in a pitched battle inside the Big Egg during the Golden Week holiday. The 55,000 tickets were hoovered up almost instantly, while live closed-circuit screenings at more than 100 cinemas across the country have also sold out.

Inoue, a seven-time Japanese amateur national champion who trains out of the Ohashi Gym in Yokohama under his father, Shingo, said he was entering the bout with a sense of calm.

“I’ve done everything I needed to do, so I don’t really have any particular feelings about it right now,” he said Thursday. “I get the impression that Nakatani has had some really good training. I myself have also had some really great training.”

The Monster will be making his seventh defense of his WBA, WBC, IBF and WBO titles at 122lb against a rangy southpaw widely viewed as his most dangerous opponent in years. Nakatani brings physical advantages in height (three inches), reach (one inch) and age (five years), while his left-handed stance looms as a serious factor. Luis Nery and Ramon Cardenas have troubled Inoue with counter lefts in the past, even if both were ultimately overwhelmed once he found his rhythm.

There have also been brief flashes of vulnerability. Inoue, who had four bouts in 2025, has been dropped in recent outings, most notably by Cardenas last year. After winning 11 fights in a row by knockout, he was extended the distance in wins over Murodjon Akhmadaliev and Alan David Picasso, with the latter performance drawing rare muted reviews.

On Thursday, Inoue framed the upcoming fight as an opportunity to reaffirm his standing.

“I want to prove that I’m still Naoya Inoue,” he said.

The bout has captured the attention of the broader Japanese public, touted breathlessly as 「世紀の一戦」 – the “Fight of the Century” – by the country’s big five national sports dailies. That anticipation has filtered down to street level. In Kanagawa prefecture, residents of Zama and Sagamihara – the neighboring home towns of Inoue and Nakatani – staged a City Border Challenge festival, complete with a lighthearted mayoral showdown on a robot boxing machine before hundreds of locals.

Japan’s boxing heritage is a robust one, with an extended lineage of great champions including Yoshio Shirai, Fighting Harada, Masao Ohba, Yoko Gushiken and Shinsuke Yamanaka. But even amid a modern boom, Inoue sees Saturday as a chance to widen the sport’s appeal.

“I want to engrave my fighting spirit in your memory,” he said. “I think there will be a lot of fans who are coming to see a boxing match for the first time. I want to show them how exciting and amazing boxing can be, and how thrilling a match can be when top fighters compete against each other.”

Nakatani, a three-division world champion at flyweight, super-flyweight and bantamweight who moved to Los Angeles as a teenager to train under Rudy Hernandez at the LA Boxing Gym in Little Tokyo, said he was embracing the scale of the occasion and the challenge.

“I don’t think there are many boxers who get to stand in a place like this,” he said. “I’ve been building up the training camp while enjoying myself and feeling grateful. It’s been a fulfilling training camp.”

He added that his preparation had gone smoothly, including the final stages of weight management before Friday’s weigh-in.

“My weight management is going smoothly. I just need to lose a few hundred grams more,” he said.

The scale of Saturday’s promotion extends beyond the gate. While exact purses are not publicly disclosed, Inoue’s earnings have surged alongside his profile. Sportico placed his 2025 income at around ¥9.7bn ($62m) including endorsements, while his previous Tokyo Dome appearance against Nery in May 2024 was said to have generated more than ¥1bn when commercial revenues were included.

Inoue’s takehome for Saturday is expected to surpass even his recent Saudi payday, underlining both his drawing power and the financial growth of Japanese boxing – a shift his longtime promoter, the former world champion Hideyuki Ohashi, described Thursday as “a world full of dreams” compared with his own era.

Nakatani, known for his quiet demeanor and love of ocean fishing, has been installed as roughly a 3-1 longshot in the fight. In a poll of 10 former Japanese world champions conducted by Sports Hochi, all 10 picked Inoue to win. But on Thursday, the challenger appeared unbothered to be overshadowed while angling for the biggest catch of all.

“On 2 May, the lives that Naoya and I have built up until now will clash,” he said. “My motivation is how many people will be moved by this. I want to fully demonstrate that.”