What do we have to do to get Japanese on iOS?

Hi!

I've been using Swiftkey for years on Android and just recently had to get an iPhone for work and found extremely puzzling the fact that after all these years iOS still does not have Japanese support.

Is there a reason for this? Like a system/OS/Software related reason? Or is it because you don't feel it is needed or important enough? 

Could you please just let us know whether it is being worked on or if we should just give up on it?

If it's a money thing could you put a price on it? I'm sure lots of users would be willing to pay for Japanese support on iOS if there were reasons causing it to be more difficult to implement than on Android. I know I would pay to even beta test it. Stuff like this greatly impacts productivity and is more than worth the money in my opinion.