The Tokyo board of education has labeled two history textbooks by Jikkyo Shuppan Co. as inappropriate for public high schools because they state some local governments are forcing teachers to sing the national anthem and display the Hinomaru flag.

Teachers nationwide have been disciplined for not displaying the national flag or singing "Kimigayo" at school ceremonies, as ordered by their local authorities, and many have sued in vain. Among them were 13 former Tokyo teachers whose punishment meted out by the metropolitan government was upheld in June 2011 by the Supreme Court. They thus failed in their attempt to be rehired after violating a metropolitan directive.

Public high schools normally select the textbooks they wish to use and ask their local board of education for approval. But if the board withholds consent, the schools cannot use them, as might be the case for the two history textbooks after Thursday's decision by the Tokyo board.