Bob Arum talks about Naoya "Monster" Inoue the same way when he used to rave about Manny Pacquiao.

The Hall of Fame promoter believes the unbeaten Japanese fighter is "an all-time great in the prime of his career."

Slated to face Marlon Tapales for the undisputed world super-bantamweight titles on 26 December at the Ariake Arena in Tokyo, Inoue looks poised to impress once again, according to Arum, who was Pacquiao's promoter for over a decade.

"The sensational Naoya Inoue astounds with every performance," Arum said during the official announcement of the mega fight that will have all four crowns on the line.

Inoue holds the World Boxing Council and World Boxing Organization straps while Tapales has the World Boxing Association and International Boxing Federation belts.

Having already been crowned as undisputed champion in the bantamweight class, Inoue is attempting to become only the second fighter to achieve undisputed status in a second division.

Like Inoue, the underdog Tapales is also attempting to hit a career milestone by becoming the first Filipino undisputed titleholder.

But Arum feels it's not going to happen as Inoue should hurdle the "tough task" by hurdling "the tough (and) powerful champion (Tapales) with flying colors."

Inoue, packing a 25-0 record with 22 knockouts, yesterday took a break from his training by attending a press conference to officially announce his date with the Filipino southpaw.

Representing Tapales during the affair was American Sean Gibbons, who played a vital role in arranging the mouthwatering matchup.

Inoue didn't mince any words in his assessment of the Tapales bout.

"I want to show my overwhelming power and win, even in a fight like this where becoming undisputed champion in a second division is on the line," he said.

Not only that.

Inoue vowed to "knock him out."

Tapales, toting a 37-3 mark with 19 knockouts, became a two-belt titlist last April by upsetting Murodjon Akhmadaliev of Uzbekistan in San Antonio, Texas.

Currently holed up in Las Vegas, Tapales and his team — made up of lead trainer Ernel Fontanilla and promoter JC Mananquil — are arriving in Manila on 8 November and will immediately proceed to  Baguio City for the continuation of training camp.