Inoue targets undisputed world bantamweight title against Butler

The fierce-punching Inoue, nicknamed "Monster", is aiming to become the first undisputed bantamweight world champion in modern boxing history by adding Butler's WBO title to his own WBC, WBA and IBF belts.

The unbeaten 29-year-old has previously said that he intends to move up to the super-bantamweight division after capturing all four bantamweight belts and he is confident he will complete his mission on Tuesday.

"Having all four belts will prove that I am the number one bantamweight, so for me this belt is very necessary," Inoue told reporters in Yokohama.

"When I have all four belts then I will decide what comes next, whether that means moving up to super-bantamweight or whatever."

Victory for Inoue would make him only the ninth undisputed world champion since the four-belt era began in 2004, and the first in the bantamweight division.

He claimed the WBC title by demolishing Philippines veteran Nonito Donaire inside two rounds in his previous fight in June.

The 34-year-old Butler took the previous champion John Riel Casimero's vacant WBO title when he beat Jonas Sultan by unanimous decision in April.

He was elevated to full champion the following month when the WBO stripped Casimero of the full title.

Butler said he is targeting his own place in boxing immortality when he steps into the ring with Inoue.

"It's not only that I'd be the first bantamweight to do it, I'd be possibly the first Englishman to win all four belts in this era," said the Ellesmere Port fighter.

"I think the last person to be undisputed was Lennox Lewis. Since then, no one's done it in the four-belt era so it's a massive fight for myself and a massive fight for England."

Inoue became the first Japanese boxer to top Ring Magazine's prestigious pound-for-pound rankings as the best fighter across all weight divisions after his masterclass against Donaire.

He floored Donaire at the end of the first round and then continued the onslaught into the second, dropping him again with a juddering left hand that persuaded the referee to stop the fight.

Inoue will go into Tuesday's bout as the heavy favourite but he warned that Butler's style is "very different to Donaire's".

"He is someone who uses the full 12 rounds," said Inoue.

"Of course, I'm prepared to beat him even if it's a long fight. Whether I win by knock-out or on points, I want to show the excellence of boxing," he added.

"I want to give a boxing display unlike anything that's gone before."