Air China: London (LHR) to Tokyo (NRT) for £1,473 return in Business class
 

Very rarely we find business class flight deals to Japan.

Air China will take you to Tokyo - with a connection in Beijing - for £1,473 return. You will depart on 17/11 and return on 29/11 and this fare can be booked via skyscanner.

This may not be the cheapest you will get to visit the country (when considering previous sales from the Nordic countries) but nevertheless it is a good deal to depart from London Heathrow.