Because of low occupancy AM switched their NRT-TIJ-MEX service to NRT-MEX direct, but because of Mexico City's high altitude they kept MEX-TIJ-NRT on the way back. Just for fun, when I try to book TIJ-NRT round trip (yes, on the way back it would be NRT-MEX-TIJ), but strangely, the website won't let me book it (says 0 flights available). Funny thing, is that I am able to book flights to NRT from other Northern Mexican cities (like Ciudad Juarez). This seems very strange to me, considering there could still be some (albeit little) demand for NRT-TIJ/TIJ-NRT passengers. Even if there isn't, why would they want to block people from booking this flight?