He said: "Of course, there is much more than foreign London Underground maps in my book, but this topic seemed to fit in well with Mark's general theme.
I've attached scans of the all-Japanese map, feel free to put one up if you like. The people who designed this were too mean to give us permission to include it in the book, which is a shame as it deserves a wider audience. Unless you have any Japanese visitors to your blog, we will never know what the mistakes are!
There are lots of other places in London for tracking down strange mutant Underground maps, the Japan Centre at Piccadilly Circus is always worth a look, and there are two large international bookshops near Regent Street, one at Great Marlborough Street (behind the back entrance to Oxford Street M&S) and one in Warwick Street."
Cheers for that tip Max and if there are any Japanese readers around maybe you can see there were any mistakes!