A popular Japanese online game is labeling the waters between the Korean Peninsula and Japan as the “Sea of Korea.”

Japan’s Sankei Shimbun said that Koei’s online simulation game “Uncharted Waters” describes the waters as the “Sea of Korea” in French.

The game, which hit the Korean market in 2005, was released in Japan last month.

Ultra-rightist Japanese groups are registering complaints about the description. But the game developer said that it has no plans to change the label, since the description is based on an existing ancient map.