The fighter, popularly known as the "God of Left", has stated that he wants "strong opponents" this year and has indicated that one such opponent could be Cuban sensation Guillermo Rigondeaux (15-0, 10). Yamanaka said that he saw Rigondeaux's recent bout with Hisashi Amagasa and it seems that watching it has inspired Yamanaka to try and get himself a bout with the Cuban double world champion.
Although a bout Rigondeaux would likely see Yamanaka to moving to Super Bantamweight it's hard to imagine that will be a real problem for the southpaw from Tokyo. He is, after all, a big Bantamweight and would have 1" in reach over Rigondeaux as well as 3½″ in height advantage.
Whilst Rigondeaux is one option that Yamanaka appears to want it's not his only option. Another is that he'll attempt to unify his world title with one of the other champions. At the moment it seems a deal is done for WBA "regular" champion Jamie McDonnell (25-2-1, 12) and WBO champion Tomoki Kameda (31-0, 19) and if Yamanaka wants to unify with of those champions he will have to wait. Notable if Tomoki wins Yamanaka would have to travel to unify with him, due to the JBC still enforcing a ban against the Kameda brothers, however if McDonnell wins there is a real possibility that the Englishman will travel. Another option would be that Yamanaka chases a unification with unbeaten IBF champion Randy Caballero (22-0, 13), however Caballero will likely have a mandatory later this year. A third option could see Yamanka fight WBA "super" champion Juan Carlos Payano (16-0, 8).
Although nothing is yet to be set in stone we do know that Yamanaka does have some free time having taken care of any mandatory obligations late last year and is free to hunt the biggest and best bouts that are available. It's clear that he wants a big name opponent and Rigondeaux would be perfect for that and a win over the Cuban would make Yamanaka a world famous name whilst a loss would be far from shameful.
(Image courtesy of http://news.livedoor.com)