Almost every textbook mentions that a large number of people were killed at Nanking. However, like every other event described in Japanese history textbooks, it is not covered at great length. The education system in Japan is aimed towards entrance examinations that require students to memorize a regurgitate facts.

Since 1982, the Japanese education ministry has required textbooks to conform with the "Neighboring Country Clause" (近隣諸国条項): Textbooks ought to show understanding and seek international harmony in their treatment of modern and contemporary historical events involving neighboring Asian countries (近隣のアジア諸国との間の近現代の歴史的事象の扱いに国際理解と国際協調の見地から必要な配慮がされていること).

Textbooks published since the 1980's mention that large numbers of Asian civilians were killed by Japan's invasions and the Nanking massacre is also mentioned.

A Stanford University study of America, Japanese, Korean, and Chinese history textbooks found that Japanese textbooks were the least nationalistic:

Far from being nationalistic, Japanese textbooks seem the least likely to stir patriotic passions. They do not celebrate war, they do not stress the importance of the military, and they tell no tales of battlefield heroism. Instead they offer a rather dry chronology of events without much interpretive narrative.

Japanese textbooks are deliberately written in this somewhat subdued manner, partly to avoid overt interpretation and because they are aimed at preparing students for university entrance examinations. Nonetheless, Japanese textbooks do offer a clear, if somewhat implicit, message: the wars in Asia were a product of Japan’s imperial expansion and the decision to go to war with the United States was a disastrous mistake that inflicted a terrible cost on the nation and its civilian population. Indeed, that basic tale is what prompted revisionist critics to author their own textbooks to correct what was seen as a “masochistic” view of modern Japan.

Contrary to popular belief, Japanese textbooks by no means avoid some of the most controversial wartime moments. The widely used textbooks contain accounts, though not detailed ones, of the massacre of Chinese civilians in Nanjing in 1937 by Japanese forces. Some, but not all, of the textbooks also describe the forced mobilization of labor in the areas occupied by Japan, including mention of the recruitment of “comfort women” to serve in wartime brothels.

All of the nations were guilty of leaving out descriptions of events that reflect badly on themselves. It could be said that history textbooks in China and South Korea are guilty of even worse distortion, especially China's whitewashing of the millions who died under Mao's rule.

Far from Oblivion: The Nanking Massacre in Japanese Historical Writing for Children and Young Adults

Concentrating on atrocity as reflected in Japanese popular historical writing for children and adolescents since the 1960s, this essay argues that such war crimes are far from ignored. Representations of the Nanking Massacre in particular, and of Japanese World War II atrocities in general, have been widely mobilized in Japan to inculcate an anti-war philosophy.