WI Muslim/christian Ryukyu Kingdom?

What would happen if the Ryukyu islands converted to islam or christianity, thanks to muslim or christian merchants? Would Japan still conquer it? Could a separated Ryukyu identity survive japanese assimilation policies?

 

Ryukyu would probably see themselves as too distinct from Japan to tolerate a continuous annexation. Even if Japan conquered them anyway, it's possible that they might eventually lose control of these islands like they did with all their other colonial possessions, like Korea and Taiwan.