Yamanaka has been the champion since November 2011, when he beat Christian Esquivel for the then vacant title. Since then he has become one of the stars of Japanese boxing and his 5 year reign at the top is the longest active reign of any male world champion. That reign hasn't just been long but it's also been a distinguished one with defenses against Vic Darchinyan, Tomas Rojas, Malcolm Tunacao, Suriyan Sor Rungvisai, Anselmo Moreno, twice, and Liborio Solis.
Aged 34 Yamanaka is one of the elder statesmen of Japanese boxing, yet is regarded as one of the truly elite level fighters from the country. In the ring he can be a bit predictable, lining up his vicious left hands which are his most potent weapon. Although a very left hand dominant fighter Yamanaka has got under-rated skills and can rely on them when needed, as he did against Solis, and can also win a war, as he did in his second bout with Moreno.
Although still a top fighter, and probably the best Bantamweight on the planet, Yamanaka has shown flaws in recent bouts. He has been dropped in his last two bouts, was fortunate to over-come Moreno in their first meeting and was given real fits by Suriyan. Despite those flaws Yamanaka has always found a way to come out on top at world level, and has won his last 21 fights, with 16 stoppages in those contests.
Whilst Yamanaka is widely regarded as the best Bantamweight on the planet much less is known about Carlson, despite the fact he too is on a long winning run, winning his last 22 bouts following a loss on his debut. Notably that loss was fought well above the Bantamweight limit, and in fact many of Carlson's early career bouts were fought in and around the Super Bantamweight division. During his 22 fight winning run Carlos has fought in both the US and in Mexico.
Whilst Carlson has fought internationally the competition that he has faced has been dire. The most notable names he has faced have been the likes of Javier Gallo, Jose Cen Torres,Miguel Tamayao and Giovanni Caro. Worryingly he has also been dropped in some of his bouts so far, and by much lesser punchers than Yamanaka.
Sadly footage of Carlson is relatively limited, though he has appeared on TV before. One of those televised fights saw him take on Aaron Olivares. The bout showed that Carlos is offensively wild and although he can seemingly punch his defense is poor, his shots are wide, his feet cross and there was little in terms of world class ability on show. He has improved since that bout, but he's still a relatively open fighter and was dropped by Carlos Melo only a few fights back.
Whilst it's hard to read too much into Carlson's ability from the footage out there he has been down against limited opponents often enough to suggest he won't be able to withstand Yamanaka's power. With that in mind we're expecting to see a relatively easy stoppage win for the Japanese fighter who will likely return later in the year seeking to tie Gushiken's Japanese record, and maybe even break it before the end of 2017.