WBC already maneuvering to make this match-up for the vacant bantamweight title once Junto Nakatani makes his expected jump up to challenge Naoya Inoue at 122lbs. Nasukawa is the #1 contender, and Naoya's younger brother Takuma just leapfrogged from #7 to number two.
If he were to beat Takuma, it perfectly sets up a Japanese mega-event if and when Tenshin wants to move up and challenge Naoya (presuming Junto is unsuccessful in dethroning their countryman). This would make Nasukawa the only person afaik to share the ring with the longtime p4p #1 from a generation past (Floyd Mayweather, who knocked him out in an exhibition match in 2018) and the current p4p #1.
It really do be like that sometimes. Ricky Hatton = straight B power. Matthew Hatton = D+ You do have sibling pairs where they both hit very hard (the Márquez and Klitschko bros notably come to mind). But the distribution can also be wildly lopsided.
Difference in technique, but from my understanding they also had the same trainers throughout their amateur careers. So I hypothesize that it´s down to their boxing IQ. Brothers who are lesser punchers are usually the lesser boxers too.
I still think this is a play by Teiken to convince Estrada who is likely arguing over money to accept the offer to fight in Japan or they will just go with Tenshin vs Takuma if needed. Estrada has minimal leverage here as he's ranked below. In the end, I think it becomes Salas vs Takuma for IBF and Tenshin vs Estrada/Cain/Gonzalez for WBC.
Tenshin Nasukawa by UD but this fight will never happen I think. It's more and more possible a fight between Nonito Donaire and Takuma Inoue for the WBA Regular belt.