KIX, NGO and NRT have all varying routings when going eastbound. NRT goes usually via Khabarovsk area, but KIX and NGO may go via Beijing and Seoul as often there is a easterly blowing jetstream over the Korean peninsula. Westbound all these flights most often go via Khabarovsk.
Of course, as always, operators choose routing on day-by-day basis as a compromise of the wind conditions on different available routings (=flight time), overfly fees and as noted before, also political reasons.