What kind of special meal? You may be disappointed with vegetarian tho, a recent trip report (LAX-KIX) has only the following with VLML type

These are the main meal.



That's it.

Second Meal


Basically all cold dishes, the economy ones seem better based on google search.

I don't think Japanese carriers caters to vegetarian meals well, even NH F offering looks bland. You'll still get good service but FA can't do much with whatever is catered. If the food disappoints, you can always order additional light snacks but be mindful they may not fit your dietary criteria. Check the regular menu online too.