The Panamanian won the title in Japan last year, when he stopped Takashi Uchiyama (24-2-1, 20) [内山 高志], and has defended it once, out pointing Uchiyama in a rematch. Given those wins over the popular "KO Dynamite" it's really understandable as to why a return to Japan would make sense for Corrales and why a Japanese promoter would want the switching hitter to return to the Land of Rising sun again.
The sources didn't seem to speculate on a date but did, surprisingly, reference Hidenori Otake (27-2-3, 12) [大竹 秀典] as a possible challenger. We don't imagine that as being correct, given that Otake's next bout will be at Super Bantamweight, however the WBA rankings do seem to lack Japanese fighters in and around the Super Featherweight division. In fact at the moment only Uchiyama and Takashi Miura (31-3-2, 24) [三浦 隆司] have WBA rankings at 130lbs, though of course the WBA have seriously over-looked Masayuki Ito (20-1-1, 9) [伊藤 雅雪] and Kenichi Ogawa (20-1, 16) [尾川 堅一].
There is also the chance that the bout could see a non-Japanese fighter face Corrales on Japanese soil.
At the moment it's a waiting game and it will seem likely that Corrales will have been given a number of offers, and will be able to pick his prefered choice from those options.
(Image courtesy of boxmob.jp)