Japanese publishers and distributors of electronic books are increasingly alarmed by the upcoming consumption tax hike in the absence of a system to tax e-books and other digital content purchased from overseas vendors such as the U.S.-based Internet giant Amazon.com Inc. and Japanese online vendor Rakuten Inc.'s Canada unit.

With the consumption tax to rise to 8 percent in April from 5 percent now, and to 10 percent in October 2015, concerns have been rising over the growing taxation disparity, which publishers see as a threat to fair competition.

At a public forum held in late November in Tokyo, Tsuguhiko Kadokawa, chairman of Kadokawa Corp., proposed that overseas companies involved in the Japanese market should also pay taxes. He was among about 100 people, including members of the Diet and online distributors, seeking "fair taxation" of overseas businesses.