If you want a cheap flight from Inverness to Tokyo, you've got one airlines to choose from.
New Tokyo International Airport is just one of the airports in Tokyo. If you're not set on a specific airport, try changing your search from New Tokyo International Airport to Tokyo to see a broader range of flights – they might be cheaper. It usually takes about 18 hrs 30 mins to fly 9127 km to New Tokyo International Airport.
There are about four flights to or via Tokyo every week, so you have plenty of options.
If you're planning on going to Tokyo during this time, you could take a look at other airport options. Or you could try to get a last-minute bargain.