Had a great chat with Masaki who works as a pre-sales manager in Japan. He and his co-authors spotted a gap in the market where there were no Instructional Qlik Sense books written in Japanese. So they decided to write one themselves, they had a few challenges on the way such as what material to include without the book being 2000 pages long but the rest is history, you can go to all of the popular online book stores and buy a copy. What a great example of  entrepreneurial spirit and go get attitude.