Today that bout was confirmed as as Shinsei Promotions held a press conference with Yamanaka to announce the contest.
The bout, as previously reported, will take place in Kobe and the fighter himself spoke about how delighted he was to be able to fight in the area for his first defense. He also seemed to be impressed by Calleros, who had fought in Japan last year when he lost to Tatsuya Fukuhara [福原 辰弥] in an absolute thriller, with Yamanaka taking the title from Fukuhara.
At the moment we've not got details on which TV channel, if any, will show the fight but it's expected that the bout will get some air time, even if it is left to a regional channel in Kansai, where Yamanaka could become one of the boxing focal points given the retirements of several local stars in recent years.
At the time of writing there has been no mention of any under-card bouts, though there is a chance that either Reiya Konishi (15-0, 5) [小西伶弥] or Shun Kubo (12-1, 9) [久保隼] will be in action on the card.
(Image courtesy of daily.co.jp)