March 22 IBF Featherweight title fight Angelo Leo vs Tomoki Kameda confirmed?

Although not officially announced yet, it seems like Angelo Leo's IBF featherweight mandatory defense against Tomoki Kameda will be held on March 22nd at Yamato Arena in Osaka, Japan.

My news sources are all Japanese, but to summarize:
1) Few weeks ago, Kameda hinted that he's aiming for a world title fight in March. Kameda is currently the mandatory challenger for IBF titlist Angelo Leo.
2) Two days ago 3150xLUSH BOMU vol. 4 was announced on Twitter for March 22nd at Yamato Arena in Osaka for a "mixed battle event of boxing and music". By coincidence, today is also 3150xLUSH BOMU vol. 3 which has the vacant super flyweight IBF titlematch.
3) For those who aren't familiar, 3150 promotions is a boxing promotion founded by Koki Kameda, who is Tomoki's eldest brother and a retired former world titlist himself. Along with his younger brother, he also promotes the Shigeoka brothers and more.

If this is correct, I am rather surprised Top Rank allowed Leo to fight in Japan instead of their own card.