Japan's ambassador to France, Yoichi Suzuki, said he "deeply regrets that this exhibition is taking place", saying it promoted "a mistaken point of view that further complicates relations between South Korea and Japan".
Up to 200,000 women from Korea, China, the Philippines and elsewhere were forced into brothels catering to the Japanese military in territories occupied by Japan during World War II, according to many mainstream historians.
Franck Bondoux, director of the Angouleme International Comics Festival in western France, told AFP that Japan had not asked for the expo to be cancelled.