Take Two Steps to the East, aaaannnd relax!
Yes, Japan would be a good fit both economically and for leisure travel in both directions. Someone mentioned the Lake District, witness the numerous Japanese tourists flocking to visit Wordsworth's and Beatrix Potter's homes year round, they have signs and books in Japanese at many places in the Lakes. And we drive on the correct side of the road for them, too.
Whilst Japan is rightly an aspiration, I would be a little concerned right now about the lack of progress to secure a Shanghai route after it looked to be in the bag around the time of the Hainan launch in the summer. Various senior people suggested publicly that it would commence shortly, but there has been no announcement for 2017. Plus the fact that all the applications were for China to London services in the recent open skies deal. We have taken two steps forward in the Easterly direction over the past 12 months, we may now be in a pause rather than one step back.