
Naoya Inoue and John Riel Casimero are among the most accomplished and exciting boxers in the lighter weight classes in recent years. Both men have held world titles in multiple divisions and have built reputations for power, skill, and an entertaining fighting style that draws fans worldwide.
While a showdown between them has long been rumored, it has yet to happen in the ring. This article offers a fact-based, in-depth look at their respective careers, strengths, championship achievements, and why fans remain eager to see them face off.
Reputable sources for this piece include BoxRec.com, BBC Sport, ESPN, The Ring Magazine, and official boxing sanctioning body records.
Naoya Inoue: The Monster of Boxing
Naoya Inoue (26-0, 23 KOs) is one of Japan’s most celebrated boxers. Known for his devastating punching power and clinical technique, Inoue has won world titles in four weight classes as of early 2024.
Nicknamed “The Monster,” Inoue first gained international attention by winning his first world title (WBC Light Flyweight) in just his sixth professional fight. He quickly moved up to claim belts at super flyweight and then dominated the bantamweight division.
His most high-profile performances include two wins over Nonito Donaire—a dramatic 2019 Fight of the Year unification bout and a 2022 rematch he won by knockout. In 2023, Inoue moved up to super bantamweight, defeating Stephen Fulton to claim unified titles before stopping Marlon Tapales to become undisputed in the division.
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Key Titles Won:
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WBC Light Flyweight
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WBO Super Flyweight
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WBA, IBF, WBC, WBO Bantamweight (Undisputed)
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WBC, WBO, WBA, IBF Super Bantamweight (Undisputed)
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Sources: BoxRec, BBC Sport, ESPN
John Riel Casimero: The Filipino Warrior
John Riel Casimero (33-4, 22 KOs) is a three-division world champion from the Philippines known for his unpredictable, aggressive style and strong knockout record.
Casimero has won world titles at light flyweight, flyweight, and bantamweight. His power and unorthodox approach have made him a dangerous opponent for anyone in the ring.
One of Casimero’s most notable wins was his 2019 third-round knockout of Zolani Tete in the UK to win the WBO Bantamweight title. That victory raised hopes for a unification bout with Inoue, which was discussed and even planned for 2020 before the COVID-19 pandemic and contractual disputes prevented it from happening.
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Key Titles Won:
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IBF Light Flyweight
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IBF Flyweight
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WBO Bantamweight
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Sources: BoxRec, The Ring, BBC Sport
The Unfulfilled Showdown
Boxing fans have long wanted to see Inoue and Casimero share the ring.
After both men held bantamweight world titles in 2020, there were negotiations for a unification fight. The COVID-19 pandemic disrupted plans, travel restrictions made it unfeasible for a time, and eventually the sides failed to finalize terms.
Casimero fought Guillermo Rigondeaux in 2021 in a tactical, cautious match that he won by split decision. Inoue, meanwhile, kept collecting titles and eventually became the undisputed bantamweight champion before moving up in weight.
As of 2024, no fight between them has been officially scheduled or confirmed.
Sources: ESPN, BBC
Styles Make Fights: How They Compare
While they’ve never fought, boxing analysts have broken down their styles in detail:
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Naoya Inoue is renowned for his textbook technique, timing, and finishing ability. He delivers accurate, devastating combinations and is patient in setting up knockouts.
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John Riel Casimero is known for unpredictability, explosive power, and a willingness to brawl. He can be difficult to read because of his feints and irregular rhythm.
A matchup between them remains intriguing because it would pit Inoue’s polished precision against Casimero’s raw power and unorthodox attack.
Sources: The Ring
Why the Fight Hasn’t Happened Yet
Several factors have prevented this anticipated matchup:
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Promotional/Management Differences: Inoue has worked with Top Rank (Bob Arum) and Ohashi Promotions, while Casimero’s representation has changed over time.
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Weight Class Moves: Inoue has since moved up to super bantamweight. Casimero has competed at bantamweight and super bantamweight but has not fought for world titles in the higher division since leaving bantamweight.
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Contractual/Negotiation Disputes: Multiple reports indicated difficulties in agreeing on terms for the fight.
Sources: ESPN, BoxingScene
Inoue’s Current Status
As of early 2024, Naoya Inoue is the undisputed champion at super bantamweight (122 pounds), having defeated Stephen Fulton and Marlon Tapales to unify all four major belts.
He has spoken about potential defenses in Japan and possibly moving to featherweight (126 pounds) in the future to pursue further glory.
Sources: BBC Sport, Reuters
Casimero’s Current Career
John Riel Casimero has continued fighting but has not reclaimed a major world title at super bantamweight. He has campaigned internationally, winning regional bouts and seeking another chance at world-title contention.
He remains a popular fighter in the Philippines and among boxing fans who appreciate his bold personality and knockout potential.
Sources: BoxRec, ESPN
Could They Still Fight?
While Inoue has moved up in weight and solidified his status as one of the sport’s top pound-for-pound stars, fans and analysts sometimes discuss the possibility of an Inoue vs. Casimero matchup if both men align at the same weight.
However, as of 2024, no fight has been signed or announced. Any future matchup would require resolving promotional and contractual challenges.
Sources: The Ring, ESPN
Conclusion
Naoya Inoue and John Riel Casimero are two of the most accomplished boxers from Asia in modern times. Inoue’s rise to four-division champion and two-time undisputed status has made him a global superstar. Casimero’s journey as a three-division world champion showcases his power and resilience in the ring.
While they have yet to fight each other, their contrasting styles and championship pedigrees ensure that boxing fans will continue to wonder what might happen if they share the ring. Until then, both remain among the most exciting talents in boxing’s lighter weight classes.