The Japanese the Japanese Don't Know

The Japanese That The Japanese Don't Know (日本人の知らない日本語) is a manga and television series about a Japanese teacher and her students written by Takayuki Tomita and Umino Nagiko. It discusses the background of Japanese words and speech. There have been four paperback volumes as of August, 2013. It has also spawned a live action drama which aired on Yomiuri TV.

Summary
The Japanese That The Japanese Don't Know is an episodic series revolving around elements of the Japanese language such as word origins and proper uses. This is backed by a story of a Japanese teacher at a Japanese language school who frequently gets involved in scenarios with her eccentric students.

Books
Volume 1 publication date February 20, 2009 ISBN 978-4-8401-2673-1 Volume 2 publication date February 19, 2010 ISBN 978-4-8401-3194-0 Volume 3 publication date March 9, 2012 ISBN 978-4-8401-4354-7 Volume 4 publication date August 2, 2013 ISBN 978-4-8401-5268-6

Outside of Japan, it has been published in the Korean language from the original source material in the Republic of Korea. In addition, it has also been published in Traditional Chinese in the Republic of China.

TV drama
From July 15, 2010 until September 30, every Thursday night, the TV drama The Japanese That The Japanese Don't Know aired on Yomiuri TV (every Thursday from 23:58 until 24:38).

Whilst the drama version is based on the original comics, the main character Haruko has been involved in more problems with the teachers and students than in the comics.

Synopsis
Haruko Kano (Riisa Naka) meets an old high school teacher who suggests that Haruko would make a good Japanese language teacher and offers to help her get a job at a public school. However, he asks that Haruko works at a private school for three months before working at a public school. He gives her a textbook which is for elementary school students.

However, when Haruko shows up on her first day as a Japanese language teacher she discovers that the school is for foreign students learning Japanese. Her students ask her questions about her own (Japanese) language that makes Haruko realize that she doesn't even fully understand her native language.