Although no opponent has been mentioned for Ao it's been said that he'll be in a 10 round non-title fight. We're expecting more details to become available in the near future though it'd seem likely that it would be a Lightweight fight as Ao continues to build towards a 3rd divisional world title.
Like Yamanaka, Ao is in a US training camp. He'll be there until mid-March before returning to Teiken for the final part of training.
Whilst no opponent has been named a story has said that that he wants a fight that can appeal to fans, so this should mean someone a little bit better than Edgar Alejandro Lomeli who Ao stopped in a round on the under-card of Yamanaka's last defense.
As for Yamanaka we've been hearing rumours that he'll be fighting Belgian Stephane Jamoye (25-4, 15) though this fight does seem a bit unlikely considering Jamoye lost last time out to Karim Guerfi in a European title bout. Despite this loss Jamoye has some how retained a #3 ranking with the WBC so it's not a bout that the WBC would refuse if Yamanaka and Teiken did want it.
A further rumour for this card is that it will be on the same show as Hozumi Hasegawa's (33-4, 15) IBF Super Bantamweight title challenge against Kiko Martinez (30-4, 22). We'll admit that that would be a fantastic card if it all comes together as rumoured.