I don't know if you're aware of it, but Drzewiecki Design is also planning on that airport and more! They've announced Tokyo City + Airports and those airports will include both Narita and Haneda.However, I will still announce the other two we are also working: KFLL (Fort Lauderdale-Hollywood Int'l) and Narita RJAA. KFLL we expect to release the first by the end of this year and RJAA by spring 2020.
I don't know how far you are into development with Narita, but if it's not too far maybe it's better to focus on other airports instead. As good as LatinVFR is, if Drzewiecki releases their Tokyo Airports I'll be buying that one. That would be a miss for LatinVFR while it could be a hit on another airport.