The process for publishing a textbook in Japan is the following: first, publishers write a draft of a textbook. Then the textbook has to be "approved" by the Ministry of Education. MoE may outright refuse to approve the book, or approve the book subject to modification.
Out of the 16 new history textbooks for Japanese high school students, not one of them says that Comfort Women were forcibly drafted by the Japanese military. Also, modification requirement was added on to 5 Japanese History textbooks with respect to the number of deaths in the Rape of Nanking, with the MoE opinion that states "the number did not take various different theories as to casualties into enough consideration."