If you want a cheap flight from Doncaster to Tokyo, you've got two airlines to choose from.
Tokyo Haneda International Airport is just one of the airports in Tokyo. If you're not set on a specific airport, try changing your search from Tokyo Haneda International Airport to Tokyo to see a broader range of flights – they might be cheaper. It usually takes about 27 hrs 45 mins to fly 9428 km to Tokyo Haneda International Airport.
five flights go to or via Tokyo every week. The most popular airline is China Eastern Airlines but do spend some time checking all your options – they aren’t necessarily the cheapest airline to book with.
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.