By Jake Donovan

Kazuto Ioka is set for the first defense of his flyweight title as he faces Argentina’s Roberto Domingo Sosa in a scheduled 12-round bout Sunday in Osaka, Japan. 

As has been the case ever since moving up in weight, Ioka weighed in exactly at the 112 lb. divisional limit. Sosa came in at a trim 110.9 lbs.

Ioka (17-1, 10KOs) joined Koki Kameda as the lone two fighters from Japan to claim major titles in three weight classes with a hard-fought 12-round decision over long-reigning champion Juan Carlos Reveco in April. The win gave Ioka the flyweight title on his second try, with his first attempt resulting in his lone career loss, coming up short in a split decision to Amnat Ruenroeng last May. 

Three straight wins have followed for Ioka, who cut his bones as a strawweight. An ambitious schedule since turning pro in 2009, Ioka claimed his first time in just his 7th pro fight, scoring a one-sided 5th round knockout of then-unbeaten Oleydong Sithsamerchai in Feb. ’11. Three defenses followed, including a historic title unification win over countryman Akira Yaegashi in their June ’12 bloodbath

The win over Yaegashi came in the first-ever unification bout between two reigning champions from Japan, though it also marked the last time either boxer fought at strawweight. Ioka moved on to his second title reign in his very next fight, claiming a secondary junior flyweight title with a 4th round knockout of Jose Rodriguez on New Year’s Eve in 2012. 

Ioka has made a tradition of fighting on New Year’s Eve beginning in 2011, going 4-0 on the last day of the year. 

Sosa (26-2-1, 14KOs) attempts just his second crack at a major title, also making his second trip outside of his native Argentina. His lone title shot came in the United States, dropping a 12-round decision to Juan Carlos Sanchez Jr. in June ’13. 

How exactly he made it back to the title stage is open to interpretation. He is an uninspiring 2-1-1 in his last four fights, including a 12-round draw with countryman Javier Chacon in July. 

The winner of the bout will be mandated to face Reveco without the benefit of an optional defense. 

An intriguing co-feature pits three-time strawweight champion Katsunari Takayama versus Ryuji Hara.

Both fighters made weight for the all-Japan clash that could potentially steal the show. Takayama hit the scales at a trim-and-ready 104½ lbs., while Hara checked in right at the 105 lb. divisional limit.

Takayama (29-7, 11KOs) attempts the second defense of the title he reclaimed last New Year’s Eve in a 7th round knockout of countryman Go Odaira. The bout was his first since coming up just short in a savage 12-round war with Francisco Rodriguez Jr. in their strawweight unification bout last August. Their bout was universally hailed as 2014 Fight of the Year. 

For Takayama, it unfortunately meant the end of a title reign which required four tries to finally put a well-earned second championship around his waist. The hard-luck strawweight came up short on the road versus then-strawweight champs Roman Gonzalez in Nicaragua and twice versus Nkosinathi Joyi in South Africa before finally upending Mario Rodriguez in March ’13.

His first reign came way back in 2005, winning an interim title before dropping a 12-round decision to Eagle Kyowa. An interim time win over Carlos Melo a year later put him back in the mix, only to fall short versus actual titlist Yutaka Niida in their April ’07 thriller.

Still alive and kicking at 32, Takayama extended his title reign with a technical decision win over Fahlan Sakkreerin Jr. this past April. Their bout served as the chief support to Ioka’s flyweight win over Reveco; Sunday marks their fourth bout on the same show, as both are promoted by Ioka Promotions which is run by Kaztuo’s father, Kazunori Ioka. 

Hara (19-1, 17KOs) was once a red-hot prospect-turned-contender well on his way to a title shot around this time last year. That changed in an instant, when he suffered a shocking knockout loss to precocious Kosei Tanaka, who was 3-0 at the time of their fight last October and has since gone on to claim a strawweight title. 

Meanwhile, Hara rebounded with a 2nd round knockout earlier this year. It wasn’t exactly the type of fight that mandates a title shot, but still has the 25-year old confident he can reclaim past glory.

Both fights will air on TBS-Japan, although it is always a game-time decision as to whether the action will come live or via same-day tape-delay (usually by 1-2 hours). 

Jake Donovan is the managing editor of BoxingScene.com.
Twitter: @JakeNDaBox
Facebook Page: JakeBScene