FX popular with Japanese
I am guessing the average person would probably lose more than they make, and therefore to assist them these books have become very popular.
There were many books available, both written in manga style as shown in the first picture to the more serious books below.
In particular the currency pairs of USD/JPY and EUR/JPY are popular in Japan. Before the current economic crisis many Japanese also had their eye on NZD and AUD because of the large differential in interest rates between New Zealand and Australia versus Japan.